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Metrosideros polymorpha

Metrosideros polymorpha, commonly known as ʻōhiʻa lehua, is a highly variable species of flowering tree or shrub in the family Myrtaceae, endemic to the Hawaiian Islands, where it dominates native forests from sea level to elevations exceeding 2,500 meters.^[1]^[2] It exhibits extreme polymorphism, manifesting as prostrate shrubs, small trees, or tall trees up to 30 meters in height, with differences in bark texture, leaf morphology, and flower colors ranging from crimson red to yellow or white.^[1]^[3] Ecologically, it serves as a foundational species, often pioneering on recent lava flows and comprising up to 80% of the canopy in wet and mesic forests across the six largest islands: Hawaiʻi, Maui, Molokaʻi, Lānaʻi, Oʻahu, and Kauaʻi.^[2]^[4] This resilience enables it to colonize diverse substrates and climates, from arid lowlands to rainforests receiving over 10,000 mm of annual precipitation, supporting endemic birds and invertebrates through nectar and habitat provision.^[5] However, since 2014, populations have faced severe decline from Rapid ʻŌhiʻa Death, a fungal disease caused by Ceratocystis fimbriata, prompting its IUCN Vulnerable status despite global security rankings.^[6]^[7]

Taxonomy and Nomenclature

Taxonomic Classification

Metrosideros polymorpha is a species in the genus Metrosideros of the family Myrtaceae, order Myrtales.^[8]^[9] Its complete taxonomic hierarchy, following the USDA Plants Database classification system, places it within the kingdom Plantae (plants), subkingdom Tracheobionta (vascular plants), superdivision Spermatophyta (seed plants), division Magnoliophyta (flowering plants), class Magnoliopsida (dicotyledons), order Myrtales, family Myrtaceae, genus Metrosideros Banks ex Gaertn., and species Metrosideros polymorpha Gaudich. This classification reflects its status as an angiosperm in the eudicot clade, with the binomial authority attributed to Charles Gaudichaud-Beaupré, who described the species in 1826 based on specimens from Hawaii.^[10]

Varieties and Genetic Polymorphism

Metrosideros polymorpha exhibits extensive morphological polymorphism, manifested in diverse growth forms ranging from prostrate shrubs to tall trees, variable leaf textures, and flower colors including red, orange, yellow, and white. This variation has led to the taxonomic recognition of multiple varieties, though boundaries are often indistinct due to intergradation and hybridization. On the island of Hawai'i, principal component analysis of herbarium specimens reveals overlapping phenotypes among varieties, with no discrete clusters, suggesting a phenotypic continuum rather than sharp delineations.^[11] The following table summarizes key morphological characteristics of six primary varieties described for Hawai'i Island:

Variety	Growth Form	Leaf Characteristics	Inflorescence	Typical Elevation
glaberrima	Shrubs to tall trees	Ovate/obovate to elliptic, glabrous, petiolate, flat margins	Pubescent	Mid to high
incana	Shrubs to tall trees	Ovate to suborbicular, appressed pubescent, flat margins	Pubescent	Low to mid
macrophylla	Small to tall trees	Broadly ovate, large, glabrous, petiolate, flat margins	Pubescent	Mid
newellii	Shrubs to small trees	Elliptic, glabrous, petiolate, flat margins	Pubescent	Low to mid, along streams
polymorpha	Shrubs to small trees	Ovate to suborbicular, densely woolly or appressed pubescent, revolute margins	Pubescent	Mid to high
nuda	Shrubs to small trees	Ovate to suborbicular, glabrous, subsessile, revolute margins	Glabrous	High (above frost line)

These distinctions are primarily based on leaf pubescence, margin shape, and sessility, yet field observations indicate frequent intermediates, challenging strict varietal assignments.^[11] Genetic analyses underscore the species' high polymorphism, with nuclear microsatellite data from populations across the Hawaiian Islands showing that genetic structure aligns more strongly with geographic isolation by island (F_ST ≈ 0.09) than with morphological varieties or traditional taxonomy. Admixture and low differentiation among varieties indicate ongoing gene flow, facilitated by wind-dispersed seeds and bird/insect pollination, preventing complete lineage sorting. RAPD markers further reveal site-specific genetic differentiation (e.g., F=93.5 between moist, high-elevation, and dry sites), but with overlap correlating to morphological intergradation.^[12]^[11] Population genomic studies highlight the role of ancestral polymorphisms in fueling adaptive radiation, where a retained pool of ancient genetic variants—shared across taxa and islands—undergoes differential sorting under divergent selection. Genome assembly of var. incana (292.8 Mb, 28,270 genes) identified enrichment of differentiation outliers in shared ancestral alleles, supporting reticulate evolution and incomplete speciation within the complex. This genetic reservoir enables rapid adaptation to heterogeneous environments, contributing to the observed polymorphism without necessitating recent mutations.^[13]

Etymology

The genus name Metrosideros derives from the Ancient Greek words metron or metra (heartwood) and sideron (iron), referring to the exceptionally hard and durable wood characteristic of species in this genus.^[14]^[15] The specific epithet polymorpha originates from Greek poly- (many) and morphe (form or shape), denoting the extensive morphological variability exhibited by this species, including differences in leaf size, flower color, and growth habit across habitats.^[14] This variability was noted by French botanist Charles Gaudichaud-Beaupré, who described the species in 1829 during the voyage of the Uranie.^[16]

Morphology and Description

Physical Characteristics

Metrosideros polymorpha displays remarkable polymorphism in growth habit, manifesting as prostrate shrubs in boggy or windswept environments or as erect trees attaining heights of 24 to 30 meters and diameters at breast height up to 1 meter under favorable conditions.^[17]^[10] It is an evergreen species characterized by slow growth rates. The trunk may be straight or contorted, often buttressed at the base in mature specimens.^[17] Bark on mature trees is typically rough, fissured, and dark gray to brown, peeling away in thick, irregular flakes that reveal lighter inner layers, while younger bark remains smooth and light gray.^[18]^[19] Leaves are opposite, simple, and leathery, varying in shape from ovate to obovate or elliptic, with lengths of 1 to 8 cm and widths up to 5.5 cm; they emerge reddish before maturing to gray-green adaxially and paler abaxially, often featuring glabrous surfaces or dense trichomes on the underside depending on variety and habitat.^[1]^[18] Flowers are perfect and arranged in dense terminal corymbs or panicles, featuring small obovate to orbicular petals (2.5–5 mm long) and triangular sepals (1.5–4 mm), but are primarily showy due to numerous exserted stamens forming a brush-like cluster; colors span red, salmon, pink, orange, or yellow, with rare white variants.^[18]^[20] Fruits consist of woody, loculicidal capsules approximately 4–8 mm in diameter, each containing numerous tiny seeds dispersed by wind.^[20]

Variability and Adaptations

Metrosideros polymorpha exhibits extensive intraspecific variability in growth form, morphology, and physiology, allowing it to occupy habitats from sea level to over 2,500 meters elevation and from recent lava flows to established soils across the Hawaiian Islands.^[21] Growth forms range from prostrate shrubs under 1 meter in exposed, high-elevation sites to arborescent trees exceeding 25 meters in sheltered, low-elevation forests, reflecting adaptations to wind exposure, substrate stability, and competitive dynamics.^[22] Leaf morphology varies significantly along environmental gradients, with high-elevation populations featuring smaller, thicker leaves with shorter petioles and internodes to reduce transpiration and resist mechanical damage from wind and cold, traits partially retained in common garden experiments indicating a genetic basis alongside phenotypic plasticity.^[23] ^[24] Varieties differ in leaf pubescence, with pubescent forms (e.g., var. polymorpha) in wetter, cooler montane sites enhancing boundary layer insulation and water retention, while glabrous varieties (e.g., var. glaberrima) predominate in warmer, drier lowlands for improved heat dissipation and photosynthesis efficiency.^[25] Floral traits show polymorphism, including stamen filament color ranging from red to yellow, orange, salmon, or white, with quantitative variation in corolla tube length, anther size, and nectar production among varieties, as demonstrated in common garden trials where genetic differences persisted despite uniform conditions.^[26] ^[27] These floral differences may adapt to varying pollinator assemblages or abiotic factors like humidity affecting nectar viscosity. Physiological adaptations include population-specific drought tolerance, with seedlings from dry sites maintaining higher survival and growth under water stress in greenhouse assays, underscoring local adaptation despite gene flow.^[28] Varieties also diverge in responses to light and mechanical stress, with wind-exposed ecotypes exhibiting stiffer stems and reallocating biomass to roots for anchorage on unstable lava.^[29] This hypervariability, driven by ancestral polymorphisms and selection across sharp ecotones, facilitates rapid colonization and resilience to disturbance, though ongoing gene flow tempers full speciation.^[13]^[30]

Similar Species

Metrosideros polymorpha bears resemblance to other species within its genus, particularly introduced congeners planted in Hawaiian landscapes for ornamental value. Metrosideros excelsa, the New Zealand pōhutukawa, features analogous clusters of vibrant red stamens in its inflorescences and leathery evergreen leaves, though it typically attains larger stature with broader leaves and thrives in coastal conditions unlike the highly adaptable M. polymorpha.^[31]^[14] Such similarities have led to inadvertent propagation of non-native Metrosideros by nurseries unaware of taxonomic distinctions, potentially facilitating hybridization or pathogen introduction in native forests.^[32] Other Myrtaceae relatives naturalized in Hawaii, including Psidium cattleianum (strawberry guava) and Leptospermum spp. (tea trees), share familial traits like opposite leaves and myrtaceous flowers but diverge markedly in fruit type, leaf texture, and growth habit, reducing confusion in mature specimens.^[14] Metrosideros collina, endemic to the Marquesas Islands, presents a closer morphological parallel with comparable leaf arrangement and floral display but remains absent from Hawaii, limiting direct overlap.^[33] Distinguishing M. polymorpha relies on its extreme intraspecific variability, encompassing shrubby to arborescent forms across elevations, which exceeds the uniformity of these congeners.^[14]

Distribution and Habitat

Geographic Range

Metrosideros polymorpha is endemic to the Hawaiian archipelago, where it occurs naturally on all main islands except Niʻihau and Kahoʻolawe.^[32]^[14] The species is present on Kauaʻi, Oʻahu, Molokaʻi, Lānaʻi, Maui, and Hawaiʻi (the Big Island), forming a key component of native forests across these landmasses.^[6]^[34] This distribution reflects its colonization of the islands following volcanic formation, with the genus Metrosideros arriving approximately 3.9 million years ago and evolving into endemic forms adapted to local conditions.^[2] While no natural populations exist outside Hawaiʻi, the tree's presence dominates up to 80% of the archipelago's native forest cover on suitable substrates.^[6]

Environmental Tolerances

Metrosideros polymorpha exhibits broad environmental tolerances that enable its dominance across diverse Hawaiian ecosystems, spanning elevations from sea level to 2,500 meters and precipitation regimes from less than 400 mm to over 10,000 mm annually.^[21]^[35] It thrives in both wet montane forests and drier subalpine zones but avoids coastal areas with annual rainfall below 500 mm, where establishment is limited.^[3] Stand density and basal area peak on young volcanic substrates receiving 2,500 mm or more precipitation, reflecting adaptations to nutrient-poor, recently formed soils.^[3] The species tolerates a wide temperature range, including subfreezing conditions at higher elevations, with seedlings and saplings showing freezing tolerance to lethal temperatures around −8.8°C (LT50).^[36] It prefers slightly acidic soils (pH 5.5–6.5) across various textures, including well-drained volcanic cinder, rocky substrates, Histosols, and Inceptisols, but performs poorly in waterlogged or highly saline conditions.^[37]^[38] Local populations display phenotypic variation in drought response, with those from mesic sites showing constrained tolerance compared to xeric-adapted variants, though overall the tree exhibits moderate drought resistance once established.^[39] Wind tolerance is notable, allowing persistence in exposed ridges, while salt spray limits distribution to sheltered coastal sites due to low salinity endurance.^[14]^[15] These tolerances underpin its role as a pioneer species on lava flows and degraded sites, though performance in open coastal exposures remains marginal.^[14]

Ecology and Life History

Ecosystem Role

Metrosideros polymorpha, commonly known as ʻōhiʻa lehua, functions as a keystone species in Hawaiian ecosystems, comprising approximately 80% of native forest cover across the six largest islands.^[6] It establishes the foundational matrix for diverse endemic flora and fauna, serving as the primary vegetation pioneer on new lava flows where it forms near-monospecific stands that facilitate subsequent ecological succession.^[40] ^[4] The tree's extensive root systems stabilize soils on slopes and volcanic substrates, preventing erosion and aiding in the breakdown of basalt into fertile substrates, which supports watershed integrity in upper catchment areas.^[41] ^[42] Its canopy intercepts fog and rainfall, enhancing groundwater recharge and maintaining hydrological cycles essential for downstream freshwater supplies.^[43] ^[44] ʻŌhiʻa lehua provides critical habitat and foraging resources for native birds, including endangered honeycreepers such as the ʻanapane (Chlorodrepanis sanguinea), which rely on its nectar-rich flowers for sustenance and pollination.^[20] These interactions underscore its role in sustaining biodiversity, as the loss of ʻōhiʻa could trigger cascading ecosystem disruptions affecting forest structure, function, and dependent species.^[45] ^[46]

Reproduction and Regeneration

Metrosideros polymorpha reproduces sexually through bird-pollinated flowers that produce abundant nectar, attracting endemic Hawaiian honeycreepers such as the ʻiʻiwi (Drepanis coccinea) and ʻapapane (Himatione sanguinea) from the family Fringillidae (formerly Drepanididae).^[47]^[48] These pollinators transfer pollen between flowers while feeding, facilitating cross-pollination in a system adapted to ornithophily.^[20] Flowering occurs variably across morphs, with colors ranging from red to yellow, and fruits develop as woody capsules containing numerous small seeds.^[47] Seed dispersal is primarily anemochorous, with wind carrying lightweight seeds from dehisced capsules after the calyx dries.^[49] Seeds germinate readily on suitable substrates, including bare lava or as epiphytes on other trees, enabling colonization of new or disturbed areas.^[20] In natural settings, seedlings establish slowly but contribute to forest regeneration, particularly following events like volcanic eruptions where recruitment from seed has been documented.^[50] Vegetative reproduction occurs via sprouting from stems or roots of damaged or fallen trees, producing adventitious roots that anchor new growth.^[20]^[38] This resprouting mechanism enhances persistence after disturbances such as canopy dieback or fire, where basal or epicormic shoots develop into mature individuals.^[51] In cultivation, cuttings or air layers treated with rooting hormones achieve propagation success, though rooting rates vary by clone and treatment.^[52]^[18] Regeneration dynamics favor a mix of seedling establishment and vegetative resprouting, with the latter dominating in mature forests under stress like the 1970s dieback events on Hawaii Island.^[53] In post-disturbance landscapes, such as lava flows, initial recruitment often involves wind-dispersed seeds forming pioneer stands, followed by clonal expansion.^[50] Studies indicate that while seed-based regeneration is viable, vegetative modes provide resilience against recruitment failures in shaded understories or pathogen-impacted sites.^[54]

Biotic Interactions

Metrosideros polymorpha relies on native Hawaiian honeycreeper birds, particularly species in the Drepanididae family such as the ʻIʻiwi (Drepanis coccinea) and ʻApapane (Himatione sanguinea), for pollination, as these birds consume nectar from its flowers and transfer pollen between individuals.^[38]^[48] Insects also serve as pollinators, contributing to seed set in this keystone species.^[38] These interactions underscore the tree's role in supporting endemic avian biodiversity, with floral variation among varieties potentially reflecting adaptations to specific pollinators.^[47] Seed dispersal occurs primarily via wind, with small, numerous seeds released from woody capsules exhibiting anemochory; annual seed rain at forest edges can reach 63,893 seeds per square meter, of which approximately 8.7% are viable.^[55]^[56] Dispersal density declines exponentially with distance from parent trees, facilitating colonization of new lava flows, though peak release often aligns with seasonal winds in December and January on Hawaiʻi Island.^[17] While native birds may indirectly aid through habitat use, direct zoochory is minimal compared to wind.^[57] The species forms mutualistic associations with arbuscular mycorrhizal fungi, which enhance phosphorus and nitrogen uptake in nutrient-poor volcanic soils; colonization rates reach 87.5% in nitrogen-limited sites but are lower (47.5%) in phosphorus-limited ones.^[58] These symbioses support establishment on barren substrates.^[59] Herbivory by insects, including psyllids (Pariaconus spp.) that induce galls via sap-feeding, affects foliage, though defenses such as leaf trichomes and delayed greening in young leaves reduce damage.^[60]^[61] Insect herbivory can improve litter quality, influencing decomposition and nutrient cycling.^[62]

Threats and Vulnerabilities

Rapid ʻŌhiʻa Death

Rapid ʻŌhiʻa Death (ROD) is a lethal fungal disease primarily affecting Metrosideros polymorpha, caused by two distinct species of the Ceratocystis genus: the more aggressive C. lukuohia, prevalent on Hawaiʻi Island, and the less virulent C. huliohia, first identified on Kauaʻi.^[63]^[64] These pathogens invade the tree's vascular system, blocking water transport and leading to rapid wilting and death, with healthy mature trees succumbing in days to weeks after symptom onset.^[65] Initial symptoms include chlorotic (yellowing) foliage transitioning to brown, followed by branch dieback and blackened streaking in the sapwood; leaves often remain attached post-mortem, distinguishing ROD from drought stress.^[65] The disease was first observed in 2012 in the Puna District of Hawaiʻi Island, where dying ʻōhiʻa trees prompted investigation; the causal fungus, initially identified as a strain of Ceratocystis fimbriata, was confirmed through isolation and Koch's postulates by 2014.^[66]^[67] Genetic analyses later differentiated the two species in 2018, with C. lukuohia linked to synchronized, rapid crown death on Hawaiʻi Island and C. huliohia associated with slower decline elsewhere.^[63] By 2019, ROD had spread to four islands—Hawaiʻi, Kauaʻi, Maui, and Oʻahu—with detections in new areas like the Waiʻanā Mountains on Oʻahu in 2023, though the aggressive C. lukuohia strain remains absent from Oʻahu.^[68]^[69] Transmission occurs primarily through human activities, such as contaminated tools, footwear, vehicles, and firewood, facilitating long-distance spread; local dispersal may involve wood-boring insects or invasive hoofed mammals like deer and pigs, which create wounds and distribute spores via soil adherence.^[70]^[71] No evidence supports wind or bird-mediated spread as primary vectors.^[72] Since 2012, ROD has killed millions of ʻōhiʻa trees, with hundreds of thousands affected on Hawaiʻi Island alone by 2016, exacerbating habitat loss for endemic species and altering watershed dynamics in native forests.^[66]^[64] Management focuses on prevention due to the absence of effective treatments or fungicides; protocols include mandatory cleaning of gear before entering forests, prohibitions on transporting ʻōhiʻa materials, and inter-island quarantines enforced since 2015.^[73] Research emphasizes breeding ROD-resistant ʻōhiʻa varieties from surviving genotypes and restoring infected sites by removing dead trees to reduce spore loads, though high disease pressure limits natural regeneration in active outbreak zones.^[74] Ongoing surveillance by state agencies and universities has detected over 100,000 infected trees island-wide as of 2023, underscoring the need for public compliance to curb further expansion.^[69]^[72]

Other Anthropogenic and Natural Threats

Invasive plants compete with Metrosideros polymorpha seedlings for resources and alter soil conditions, reducing native regeneration in invaded areas; species such as Miconia calvescens outcompete young ʻōhiʻa by forming dense canopies that suppress light availability.^[75] ^[40] Feral ungulates, including pigs (Sus scrofa), goats (Capra hircus), and axis deer (Axis axis), damage ʻōhiʻa habitats by browsing seedlings, rooting up soil, and facilitating the spread of invasives through trampling and fecal deposition, with studies documenting near-complete prevention of seedling establishment in ungulate-accessible sites.^[6] ^[76] ^[77] Increased wildfire frequency, exacerbated by invasive grasses like guinea grass (Megathyrsus maximus) and broomsedge (Andropogon virginicus), threatens dry M. polymorpha woodlands, where fires cause over 95% crown mortality in dominant stands unadapted to recurrent burning, unlike pre-human fire regimes that were infrequent.^[78] ^[79] Habitat conversion for agriculture and development has historically reduced ʻōhiʻa extent, fragmenting populations and increasing edge effects that promote invasive ingress, though the species' broad distribution mitigates total loss.^[71] ^[80] Natural disturbances including volcanic eruptions periodically destroy ʻōhiʻa stands via lava flows, as observed in the 1983–1990 Kīlauea activity that buried thousands of hectares on Hawaiʻi Island, though the species recolonizes pioneer sites rapidly post-event.^[81] Hurricanes, such as Hurricane Iniki in 1992, inflict canopy damage and elevate mortality in remnant populations with low seedling density, amplifying vulnerability through debris-fueled secondary disturbances.^[82] Prolonged droughts stress mature trees by limiting water availability in rain-limited microsites, contributing to predisposing decline factors like poor drainage, independent of pathogens.^[83] ^[80]

Conservation and Management

Protection Strategies

Protection strategies for Metrosideros polymorpha primarily target the prevention of Rapid ʻŌhiʻa Death (ROD), a fungal disease caused by Ceratocystis species that has killed over one million trees since 2014, with no known cure.^[84] Core measures include strict hygiene protocols to halt fungal spore transmission via contaminated soil, water, or equipment. Individuals entering ʻōhiʻa forests are advised to clean footwear and gear by brushing off dirt and applying 70% isopropyl alcohol, avoiding transport of ʻōhiʻa wood, branches, or soil between islands or sites.^[85] Habitat management emphasizes minimizing tree wounds, which serve as fungal entry points, through fencing to exclude feral ungulates like pigs and cattle that cause bark damage.^[86] Statewide initiatives, coordinated by the Hawaii Department of Land and Natural Resources (DLNR) and University of Hawaii's College of Tropical Agriculture and Human Resources (CTAHR), promote public education via signage, workshops, and media campaigns to enforce "Clean, Declare, Disinfect" practices at trailheads and research stations.^[6]^[84] Regulatory actions include prohibitions on moving ʻōhiʻa materials and mandatory reporting of symptomatic trees, supported by monitoring networks that detected ROD's spread from Big Island to Kauai by 2019.^[87] In 2022, M. polymorpha was designated Hawaii's official state endemic tree, underscoring commitments to watershed protection and ecosystem restoration, though implementation relies on voluntary compliance amid challenges like tourism pressures.^[88] Federal support via the U.S. Forest Service aids in funding surveillance and ungulate control, prioritizing high-elevation forests where ʻōhiʻa dominates.^[89]

Breeding and Resistance Research

The ʻŌhiʻa Disease Resistance Program (ʻŌDRP), established in 2018 through collaboration among the Akaka Foundation for Tropical Forest and Plantation Heritage, federal agencies like the USDA Forest Service, state entities, and universities, focuses on identifying genotypes of Metrosideros polymorpha resistant to rapid ʻōhiʻa death (ROD) pathogens Ceratocystis lukuohia and C. huliohia.^[90] ^[91] The program's core strategy involves screening seedlings from diverse island populations for tolerance, with the aim of propagating resistant material for reforestation in ROD-affected areas.^[92] By 2022, a structured framework had been proposed to guide resistance development, emphasizing germplasm collection from varied habitats, artificial inoculation trials, and genetic analysis to quantify heritability of resistance traits.^[93] Initial screenings, including five trials as of 2025, have identified select genotypes exhibiting minimal foliar wilt symptoms post-inoculation, suggesting low but detectable levels of wildtype resistance in otherwise highly susceptible populations.^[94] A 2020 preliminary study screened varieties from natural populations and found evidence of partial resistance in at least one morphological variant, though broad susceptibility predominates.^[95] Ongoing efforts include outplanting screened survivors to high-ROD-hazard sites for long-term field validation of resistance stability, alongside seed collection from "escapee" trees in mortality hotspots to capture potential adaptive variants.^[96] These initiatives recognize the species' high genetic diversity across Hawaiian islands but note that breeding cycles may span decades due to slow growth and polyploidy challenges.^[97] No commercially scalable resistant cultivars exist as of 2025, with research prioritizing empirical screening over speculative genetic engineering.^[94]

Recent Policy and Scientific Developments

In July 2024, the Hawaii Department of Land and Natural Resources marked the tenth anniversary of the initial detection of Rapid ʻŌhiʻa Death (ROD), caused by the Ceratocystis labilis fungus, emphasizing ongoing state-led efforts including enhanced surveillance, quarantine enforcement, and public outreach to limit spread across islands.^[98] Federal policy advanced in 2024-2025 through the Continued Rapid Ohia Death Response Act, introduced as S.85 and H.R. 375, which mandates collaboration between the U.S. Departments of Interior and Agriculture and the State of Hawaii to fund ROD research, forest restoration, and pathogen control measures, building on prior authorizations to address over one million tree deaths.^[99] ^[100] The bill, sponsored by Senator Mazie Hirono and advanced by Representative Jill Tokuda, passed the U.S. House in September 2024, allocating resources for genetic screening and deployment of resistant ʻōhiʻa stock while prohibiting unpermitted movement of potentially infected materials.^[101] Scientifically, the ʻŌhiʻa Disease Resistance Program (ODRP), a multi-partner initiative involving the U.S. Forest Service, University of Hawaii, and nonprofits, reported progress in July 2025 on sourcing seeds from naturally resilient trees in high-ROD zones on Maui and Hawaii Island, with propagation trials yielding initial plantings for field testing.^[102] A November 2024 U.S. Forest Service webinar detailed operational advancements, including survival assessments of over 1,000 screened seedlings planted in ROD-affected sites, confirming genetic variability confers partial resistance via traits like reduced vascular staining and faster wound response.^[94] Complementary USDA Agricultural Research Service projects in Hilo, ongoing through 2025, focus on fungal isolate genomics and greenhouse inoculation protocols to accelerate resistant hybrid development, with early data indicating 5-10% heritability for tolerance in select Metrosideros polymorpha populations.^[103] These efforts prioritize empirical field validation over lab proxies, addressing prior gaps in scalable restoration amid Hawaii's diverse volcanic substrates.^[104]

Human Uses and Economic Value

Traditional and Cultural Applications

The wood of Metrosideros polymorpha, known as ʻōhiʻa, was highly valued in traditional Hawaiian society for its hardness and durability, serving as a primary material for construction elements such as rafters, posts, and beams in hale (houses) and heiau (temples).^[32]^[105] It was also carved into kiʻi (wooden images of deities), weapons, kapa (tapa cloth) beaters, and poi boards.^[106]^[6] Medicinally, infusions from the leaves were prepared as teas to alleviate pain during childbirth, while the flowers, particularly of varieties with dark red lehua, were employed for similar obstetric purposes.^[44]^[107] Young leaves addressed conditions like pallor in infants, reflecting empirical observations of the plant's astringent properties in Polynesian herbal practices.^[108] The vibrant lehua flowers and liko (young shoots) found application in crafting lei and haku (head leis), integrating the tree into ceremonial and decorative customs without evidence of broader dyeing or fiber uses specific to this species.^[6]^[14]

Commercial and Ornamental Uses

The wood of Metrosideros polymorpha, known as ʻōhiʻa, is valued for its fine even texture, density, and ability to take a good polish, making it suitable for commercial applications such as strip flooring, decking, furniture, cabinetry, and decorative posts.^[109]^[4]^[110] It has also been used historically and in limited modern contexts for fence posts, roundwood construction, and fuel, though harvesting is constrained by the tree's ecological and cultural significance in Hawaii.^[20]^[111] In ornamental horticulture, M. polymorpha is planted in native Hawaiian landscapes and urban gardens for its variable forms—from shrubs to trees up to 12 meters tall—vibrant flowers in shades of red, orange, or yellow, and role in erosion control and wildlife support.^[14]^[37]^[10] Propagation via air layering with rooting hormones enables its use in landscaping, provided conditions include full sun and well-drained, organic-rich soil, though susceptibility to diseases like Rapid ʻŌhiʻa Death limits widespread cultivation.^[1]

Cultural and Symbolic Importance

In Hawaiian Tradition

In Hawaiian mythology, the ʻōhiʻa lehua tree features prominently in a legend involving the volcano goddess Pele, who desired the handsome chief ʻŌhiʻa, already devoted to his beloved Lehua.^[112] When ʻŌhiʻa rejected Pele's advances, she transformed him into a twisted tree in jealousy; grieving Lehua was then turned by other gods into a flower adorning the tree, ensuring the lovers remained united.^[112] This tale symbolizes inseparable love and explains the belief that separating a lehua blossom from its ʻōhiʻa causes rain, as if the flower weeps for its separation from the tree.^[6] The tree holds sacred status in Native Hawaiian tradition, associated with Pele as a manifestation of her fiery domain and with Laka, the goddess of hula and forest spirits, reflecting its role in dances and rituals.^[44] Forests dominated by ʻōhiʻa were revered as wao akua, realms of the gods, where human entry required protocols to avoid spiritual repercussions.^[2] In the Kumulipo creation chant, ʻōhiʻa ecosystems support native birds like the ʻapapane, whose red feathers mirrored the lehua's hue and were woven into cloaks symbolizing chiefly status and vitality.^[113] These associations underscore the tree's embodiment of resilience, as it pioneers lava flows in Pele's wake, linking ecological endurance to cultural narratives of divine power and harmony.^[2]

Modern Cultural References

In contemporary Hawaiian performing arts, Metrosideros polymorpha (ʻōhiʻa lehua) features in works blending cultural symbolism with ecological concerns. A 2022 Master of Fine Arts thesis in Dance (Performance and Choreography) at the University of Hawaiʻi at Mānoa produced "ʻŌhiʻa Lehua," a performance art piece directed and choreographed by the artist, incorporating original music from composers with deep Hawaiian connections to evoke the tree's mythic and environmental roles.^[114] Modern music compositions have addressed the tree's vulnerability to disease. In 2020, juniors at Kamehameha Schools composed an original mele (Hawaiian song) focused on Rapid ʻŌhiʻa Death, performed by the class at the school's centennial Song Contest to promote conservation awareness among Native Hawaiian youth.^[115] Contemporary poetry reflects the tree's enduring symbolic presence amid threats. A 2016 poem published in The Hawaii Independent portrays ʻŌhiʻa and Lehua as lovers confronting devastation from natural disasters and human impacts, emphasizing themes of resilience and loss in modern Hawaiian verse.^[116]

References

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Metrosideros polymorpha ('Ohia lehua) - CTAHR
Metrosideros polymorpha is an extremely variable plant. It ranges in habit from a prostrate shrub to a 100 foot tree. Young bark is smooth and light gray.
[2]
Ohi'a lehua (Metrosideros polymorpha): A most resilient ... - USGS.gov
It is the dominant or co-dominant tree species in wet and mesic forests and is also one of the first woody species to become established on young lava flows.Missing: facts | Show results with:facts
[3]
'Ohi'a lehua | Silvics of North America
Dec 1, 1990 · 'Ohi'a lehua (Metrosideros polymorpha) is the most abundant and widespread tree in Hawaii. This slow growing native hardwood seeds freely and ...
[4]
Metrosideros polymorpha | CABI Compendium
The natural distribution is limited to the six largest islands in the Hawaiian Archipelago: Hawaii, Maui, Molokai, Lanai, Oahu, and Kauai. Location of ...
[5]
Adjustment of structure and function of Hawaiian Metrosideros ...
Aug 3, 2007 · Populations of Metrosideros polymorpha establish across a broad range of precipitation in Hawai'i – from <400 to >10000 mm per year.<|separator|>
[6]
Forestry Program | 'Ōhi'a lehua
Scientific: Metrosideros polymorpha. Conservation Status. NatureServe Heritage Rank G5 – Secure; IUCN Red List Ranking – Vulnerable. Species Information. 'Ōhi'a ...
[7]
The evolving threat of Rapid 'Ōhi'a Death (ROD) to Hawai'i's native ...
Sep 15, 2019 · Hawai'i's most widespread native tree, 'ōhi'a lehua (Metrosideros polymorpha), has been dying across large areas of Hawai'i Island mainly due to two fungal ...
[8]
'ohi'a Lehua (Metrosideros polymorpha) | U.S. Fish & Wildlife Service
Scientific Name. Metrosideros polymorpha. Common Name. 'ohi'a lehua. Kingdom. Plantae. Location in Taxonomic Tree. Genus. Metrosideros. Species. Metrosideros ...
[9]
Metrosideros polymorpha var. polymorpha - Plants of the World Online
Classification. Kingdom Plantae; Phylum Streptophyta; Class Equisetopsida; Subclass Magnoliidae; Order. Myrtales. View Order Tree opens in a new tab. Family.
[10]
Metrosideros polymorpha - Plant Detail - NTBG Database
Family: MYRTACEAE Genus: Metrosideros Species: polymorpha. Species Author: Gaudich. Vernacular: Ohia lehua, Lehuapapa, Lehuaahihi, Ahihikumakua, ...
[11]
Morphological and genetic variation within Metrosideros ...
Table 1 Morphological characteristics of the Metrosideros polymorpha taxonomic varieties found on the island of. Hawai'i as described by Dawson & Stemmermann ...
[12]
Genetic Structure of the Polymorphic Metrosideros (Myrtaceae ...
Mar 4, 2009 · The results suggest that Hawaiian Metrosideros have dynamic gene flow, with genetic and morphological diversity structured not simply by geography or taxonomy.
[13]
Ancestral polymorphisms shape the adaptive radiation of ...
Sep 8, 2021 · Hawaiian Metrosideros is a landscape-dominant, hypervariable, and highly dispersible group of long-lived (possibly >650 y) (34) woody taxa that ...
[14]
Metrosideros polymorpha - Native Plants Hawaii - Viewing Plant
ʻŌhiʻa (Metrosideros polymorpha) can be found from near sea level to over 7,200 feet on most of the Main Islands and often a major component of native Hawaiian ...Missing: ecology | Show results with:ecology
[15]
[PDF] Metrosideros polymorpha ('ōhi'a lehua)
The name Metrosideros is derived from the Greek metra, heartwood, and sideron, iron, in reference to the hard wood of the ge- nus (Dawson and Stemmermann 1999).Missing: etymology | Show results with:etymology
[16]
Metrosideros: Life & Death on the Lava Flow
Mar 25, 2021 · French botanist Charles Gaudichaud-Beaupré selected the spot-on species name polymorpha, meaning “many shapes or forms” in 1830. Other ...
[17]
[PDF] Metrosideros polymorpha Gaudich.
Part II—Species Descriptions • Metrosideros polymorpha Gaudich. hybridization and genetic polymorphism is unknown (Wagner and others 1990). The heartwood is ...
[18]
Metrosideros polymorpha - Plants of Hawai'i | Bishop Museum
Description. Key Characters: Fruit a capsule; flowers in terminal cymes; sepals and petals distinct; staminal filaments distinct; leaves opposite; ...
[19]
Metrosideros polymorpha - Wildflower Search Hawaii
This is a large evergreen tree becoming 80 ft (24 m ) tall and 3 ft (0.9 m ) in trunk diameter, sometimes larger, with compact to irregular
[20]
Metrosideros polymorpha Gaud - - Southern Research Station
'Ohi'a lehua is a variable and unusual tree found from just above sea level to 2600 in (8,500 ft) as a tree or small shrub on six of the high islands of the ...Missing: facts | Show results with:facts
[21]
Adjustment of structure and function of Hawaiian Metrosideros ...
Aug 3, 2007 · Metrosideros polymorpha dominates vegetation from sea level to greater than 2500 m elevation, on very recent lava flows as well as on soils ...Missing: ecotypes | Show results with:ecotypes
[22]
Incipient radiation within the dominant Hawaiian tree Metrosideros ...
May 14, 2014 · We examined the landscape-dominant tree, Metrosideros polymorpha, for variation at nine microsatellite loci across 23 populations on young Hawai'i Island.
[23]
Physiological and morphological variation in Metrosideros ...
Morphological characteristics such as leaf size, petiole length, and internode length decreased with increasing elevation in the field and were retained when ...
[24]
(PDF) Physiological and morphological variation in Metrosideros ...
Aug 9, 2025 · Metrosideros polymorpha, a dominant tree species in Hawaiian ecosystems, occupies a wide range of habitats.
[25]
[PDF] Contrasting Structure and Function of Pubescent and Glabrous ...
Hawaiian dominant tree species Metrosideros polymorpha varieties ... Leaf morphology along en- vironmental gradients in Hawaiian Metrosideros polymorpha.
[26]
Floral Variation across Three Varieties of the Landscape-Dominant ...
Dec 2, 2020 · Metrosideros polymorpha is known for its exceptional phenotypic diversity, with individual trees varying substantially in height, leaf size and ...Missing: variability adaptations
[27]
[PDF] floral variation across three varieties of the landscape-dominant
Dec 2, 2020 · We found significant variation in the floral morphology of. Metrosideros polymorpha in a common garden, suggesting that the variation in floral ...
[28]
[PDF] Local adaptation constrains drought tolerance in a tropical ...
Jan 2, 2020 · polymorpha demonstrates high seedling drought tolerance in some populations, providing evidence of resil- ience at the species-scale, there are ...
[29]
Varieties of the highly dispersible and hypervariable tree ...
Jul 22, 2019 · In the Hawaiian Islands, the landscape-dominant tree, Metrosideros polymorpha, displays extraordinary phenotypic differences among sympatric ...
[30]
[PDF] Varieties of the Highly Dispersible and Hypervariable Tree ...
May 28, 2019 · physical separation of ecotypes may contribute to their maintenance through reduced gene flow. Metrosideros polymorpha var. newellii ...
[31]
https://htmc1910.org/news/ulu-kanu-metrosideros/
[32]
Ohia – Lehua Mamo - Hui Ku Maoli Ola
Sep 23, 2013 · They are from the same genus and look very similar to each other. Many nurseries in Hawai'i grow these nonnative varieties, not knowing the ...
[33]
Trees to replace ohia - Punaweb
We saw Metrosideros collina all over the Marquesas, where it is endemic, and it - not surprisingly - looks very similar to Ohi'a, but with the leaves having ...
[34]
Metrosideros polymorpha var. glaberrima - Seeds Of Hawaii
glaberrima is a medium-sized or tall tree reaching heights of 10-15 meters. It is notable for its glabrous morphology, including leaves, stems, inflorescences, ...
[35]
Photosynthesis and Freezing Avoidance in Ohia (Metrosideros ...
May 2, 2018 · Metrosideros polymorpha (Ohia), the dominant tree species in Hawaiian forest ecosystems, grows from sea level to treeline (2500 m).
[36]
Freezing temperatures restrict woody plant recruitment and ...
The common and ecologically important tree M. polymorpha had a trend towards higher freezing tolerance (LT50 = −8.8 ± 0.9°C SE) than A. koa (LT50 ...
[37]
Ohi'a Lehua - Metrosideros Polymorpha - Mana Home Services
Soil: Ohi'a lehua prefers well-drained, slightly acidic soils with a pH range of 5.5 to 6.5. It can tolerate poor, rocky soils often found in volcanic ...
[38]
[PDF] 'Ohi'a lehua - USDA Forest Service
'Ohi'a lehua (Metrosideros polymorpha) is the most abundant and widespread ... Morphology of the varieties also differs; those with pubescent leaves ...
[39]
Local adaptation constrains drought tolerance in a tropical ...
Jan 8, 2020 · A quantitative analysis of phenotypic variations of Metrosideros polymorpha within and across populations along environmental gradients on Mauna ...
[40]
'Ōhi'a Lehua (Metrosideros polymorpha): A Most Resilient and ...
Feb 1, 2024 · DISTRIBUTION AND ECOLOGY. As 'ōhi'a is central in Hawaiian culture, it is also central to the ecosystems which it dominates. It is found in ...
[41]
Preserving the Sacred Bond Between People and ʻŌhiʻa
Feb 14, 2024 · Ecological role ʻŌhiʻa trees are critical to the Hawaiian ecosystem, providing habitat for various species, contributing to soil stabilization, ...
[42]
[PDF] First Report of Ceratocystis Wilt on ˋŌhiˋa (Metrosideros ...
Soil stabilization. 'Ōhi'a forests protect the upper reaches of most of Hawai'i's critical watersheds. On new lava flows, 'ōhi'a forests help break down the ...
[43]
https://www.hawaii-guide.com/hawaii-ohia-lehua
[44]
ʻŌhiʻa Lehua - Maui Ocean Center
ʻŌhiʻa lehua is also responsible for keeping water within forested areas. Their leaves are excellent at catching fog and making the water accessible for other ...Missing: functions | Show results with:functions
[45]
Ulu Lehulehu—Million ʻŌhiʻa Initiative: Protecting & Restoring ...
ʻŌhiʻa lehua is critical to maintaining the diversity, structure, and function of Hawaiʻi's native forests. This ecological foundation provides food and habitat ...
[46]
Rapid 'Ōhi'a Death - Hawaiʻi Volcanoes National Park (U.S. ...
ʻŌhiʻa is the keystone species in Hawaiian forests, and ROD has the potential to cause major ecosystem disturbances that will negatively impact watersheds, ...Missing: functions | Show results with:functions<|separator|>
[47]
Floral Variation across Three Varieties of the Landscape-Dominant ...
Metrosideros polymorpha Gaud. ('ōhi'a or 'ōhi'a lehua in Hawaii) is an evergreen tree in the family Myrtaceae and the most dominant native plant species in ...
[48]
Hawaiian Pollinators Blog | Pollinator.org
Aug 15, 2024 · Birds like the ʻIʻiwi and ʻApapane (Himatione sanguinea) are essential for pollinating the ʻŌhiʻa lehua, a keystone tree species in Hawaii's ...
[49]
Ohia | Graham's Island
Jul 25, 2021 · Eventually, the calyx will dry out and release the tiny mature seeds, to be dispersed by the winds, and hopefully grow into new ohia trees. An ...
[50]
Invasion and Recovery of Vegetation after a Volcanic Eruption in ...
In the spatter-with-tree-snags habitat (3), four species survived. Several of the Metrosideros tree snags, initially believed to be dead, resprouted from the ...
[51]
Regeneration of Metrosideros polymorpha forests in Hawaii after ...
Dec 15, 2018 · We generated 1,170 virtual vegetation plots with a 100-m radius; 541 plots in areas mapped in 1977 with trees dead or mostly defoliated (dieback) ...
[52]
[PDF] Vegetative propagation of yellow ohia lehua - CTAHR
The purpose of this trial was to determine the effect of treatments with a commercial root-promoting prod uct on the rooting of a selected yellow-flowering ohia.
[53]
[PDF] Regeneration of Metrosideros polymorpha forests in Hawaii after ...
The ecology and dynamics of the M. polymorpha dieback forest and potential mechanisms for the 1970s dieback event were sum- marized by Mueller- Dombois ...
[54]
Regeneration of Metrosideros polymorpha from seedlings to new...
Regeneration of Metrosideros polymorpha from seedlings to new trees in seven height classes. Bar plots showing the mean ± SE of log-transformed counts of ...
[55]
seed dispersal of metrosideros polymorpha (myrtaceae)
Nov 1, 1992 · Annual seed rain at the forest edge was 63,893 seeds/m2, of which 5,580 (8.7%) contained embryos and were potentially viable. Beyond the forest ...
[56]
Seed Dispersal of Metrosideros polymorpha (Myrtaceae) - jstor
1. Annual seed rain of filled (embryo-containing) and unfilled. (embryo-lacking) Metrosideros polymorpha seeds on a 20-yr-old lava.
[57]
Introduced birds incompletely replace seed dispersal by a native ...
The vegetation communities are dominated by ohia (Metrosideros polymorpha) ... polymorpha may result in higher germination rates if the seeds are deposited ...<|separator|>
[58]
Direct nitrogen and phosphorus limitation of arbuscular mycorrhizal ...
Aug 20, 2002 · The vegetation at each site is comprised of native forest and is strongly dominated by the evergreen tree Metrosideros polymorpha (Crews et al., ...Introduction · Methods · Results · Discussion
[59]
Core arbuscular mycorrhizal fungi are predicted by their high ...
Feb 25, 2022 · Core arbuscular mycorrhizal fungi are predicted by their high abundance–occupancy relationship while host-specific taxa are rare and geographically structured.
[60]
Psyllid galls on ʻŌhiʻa tree, Pariaconus spp. - Bug of the Week
Dec 5, 2022 · Galls on ʻŌhiʻa are formed by a clan of sucking insects called psyllids, members of a large order of insects known as the Hemiptera - stink bugs ...Missing: herbivores | Show results with:herbivores
[61]
Leaf Trichomes in Metrosideros Polymorpha Can Contribute to ...
Mar 9, 2020 · Leaf trichomes are known to play a role in plant defence against herbivores, including gall makers. Because gall formation can increase water ...
[62]
INSECT HERBIVORY INCREASES LITTER QUALITY AND ...
Nov 1, 2003 · Potential ecosystem-level effects of genetic variation among populations of Metrosideros polymorpha from a soil fertility gradient in Hawaii.
[63]
Real-Time PCR Assays to Detect and Distinguish the Rapid ʻŌhiʻa ...
Oct 17, 2018 · Ceratocystis lukuohia and C. huliohia are recently described fungal species that cause rapid 'ōhi'a death (ROD) of Metrosideros polymorpha, ...Missing: timeline | Show results with:timeline
[64]
New Ceratocystis species associated with rapid death of ... - NIH
Metrosideros polymorpha plants were propagated from seeds or cuttings taken ... Etymology. The name lukuohia is derived from the Hawaiian words luku ...
[65]
The Disease: Rapid ʻŌhiʻa Death - CTAHR
Crowns of affected ʻōhiʻa trees turn yellowish (chlorotic) and subsequently brown within days to weeks; dead leaves typically remain on branches for some time.Missing: first | Show results with:first
[66]
[PDF] Responding to Rapid ʻŌhiʻa Death (ROD)
Since its initial detection in 2012, Rapid ʻŌhiʻa Death (ROD) has killed millions of ʻōhiʻa trees. It is caused by two non-native fungal pathogens, ...
[67]
[PDF] Chapter 15 - Rapid 'Ōhi'a Death in Hawai'i - USDA Forest Service
Aug 12, 2022 · Rapid ʻŌhiʻa Death-affected Metrosideros polymorpha trees on Hawaiʻi Island. For. Pathol. 49. https://doi.org/10.1111/efp.12476, e12476. Roy ...
[68]
07/31/19-RAPID ʻŌHIʻA DEATH NOW DETECTED ON FOUR ...
Jul 31, 2019 · Rapid ʻŌhiʻa Death has now been detected on Hawai'i Island, Maui, Kaua'i and O'ahu since the fungal disease was first discovered in 2014.Missing: timeline | Show results with:timeline
[69]
04/10/23 – RAPID ʻŌHIʻA DEATH DETECTED FOR FIRST TIME IN ...
Apr 10, 2023 · RAPID ʻŌHIʻA DEATH DETECTED FOR FIRST TIME IN WAIʻANAE MOUNTAINS. More aggressive strain still absent from Oʻahu. To view video please click ...Missing: timeline | Show results with:timeline
[70]
Rapid ʻōhiʻa death linked to hoofed animals in UH Hilo research
Aug 17, 2021 · New findings reveal the spread of a fungal disease killing off hundreds of thousands of mature ʻōhiʻa trees (Metrosideros polymorpha) on Hawaiʻi ...
[71]
Saving 'Ōhi'a: A Case Study on the Influence of Human Behavior on ...
Oct 28, 2020 · Rapid 'Ōhi'a Death (ROD) is an emerging fungal disease that poses a significant health risk for these trees and is spread by human traffic, ...
[72]
Increasing understanding and capacity to manage and mitigate ...
Apr 30, 2025 · ʻŌhiʻa lehua (Metrosideros polymorpha) is Hawai'i's most important native forest tree - a speices of central importance to the ecology and ...
[73]
Questions and Answers on ROD - CTAHR
The only way to know if an ʻōhiʻa is infected with Rapid ʻŌhiʻa Death is to test a wood sample. The fungus that causes ROD will die when wood is heated to over ...Missing: detection | Show results with:detection
[74]
Forests with Active Rapid ʻŌhiʻa Death Infections May Be Possible
Jul 9, 2020 · “This information can help to slow the spread of the disease through effective management strategies. While surrounding disease pressure may be ...
[75]
Listening to the Hilo Rain: Impacts of Rapid ʻŌhiʻa Death on Lei ...
Apr 30, 2025 · One plant that was commonly used for lei making in Hawaiʻi is ʻōhiʻa (Metrosideros polymorpha). ʻŌhiʻa is endemic to Hawaiʻi, and likely evolved ...
[76]
Hawaiian Efforts to Restore Threatened Trees
Dec 2, 2024 · Several Hawaiian tree species are at risk due to introduced forest pests. Two of the Islands' most widespread species are among the at-risk ...
[77]
[PDF] Successful restoration of Metrosideros polymorpha (ʻ¯ohiʻa) is ...
While it is well known from many sites across Hawaiʻi that feral ungulates and exotic plants are detrimental to ʻ¯ohiʻa (Cabin ... invasive species. This is ...
[78]
[PDF] Response of native Hawaiian woody species to wildfires in tropical ...
Metrosideros polymorpha is the dominant forest tree across the elevation ... Wildland fire resulted in greater than 95% crown mortality of the dominant ...
[79]
wildfire crisis in Hawai'i - tragedy in Lahaina - NAISMA
Oct 10, 2023 · Hawaiʻi is not alone in this increasing trend of invasive grassland-fueled fires. A 2019 study found that six species of fire-prone invasive ...
[80]
[PDF] Decline of ohia (Metrosideros polymorpha) in Hawaii: a review.
Loss of the ohia canopy in some areas has resulted in a decrease in population of some native birds and increased numbers of some introduced birds. Endangered ...<|control11|><|separator|>
[81]
Invasion and Recovery of Vegetation after a Volcanic Eruption in ...
These included only two species, the native Metrosideros polymorpha and the introduced weed-tree Buddleja asiatica. Both trees spread with the same rate ...Missing: invasive | Show results with:invasive
[82]
[PDF] Draft Recovery Plan for 44 Species from the Islands of Maui ... - ECOS
Dec 17, 2021 · For the plant species that persist in low numbers, natural disasters such as hurricanes are particularly devastating. ... threat to Metrosideros ...
[83]
Decline of Ohia (Metrosideros polymorpha) in Hawaii: a review
Ohia decline appears to be a typical decline disease caused by a sequence of events. Poor drainage is probably the major cause of stress.Missing: diagnosis | Show results with:diagnosis
[84]
Rapid ʻŌhiʻa Death - CTAHR
Healthy trees appear to die within a few days to a few weeks, which is how the disease came to be called “Rapid ʻŌhiʻa Death.” This disease has killed trees in ...Missing: fimbriata | Show results with:fimbriata
[85]
Help Stop Rapid Ohia Death Across Hawaii | Info, Tips & Videos
Do the following to prevent spreading Rapid ʻŌhiʻa Death (ROD) fungus. Don't transport plants between islands. Disease spreads quickly when introduced into a ...
[86]
Rapid ʻŌhiʻa Death in Hawaiʻi - USGS Publications Warehouse
Long-term control measures also include fencing of some forests to reduce the amount of wounding to 'ōhi'a trees by feral cattle and pigs that allows entry of ...Missing: Ohia | Show results with:Ohia<|control11|><|separator|>
[87]
[PDF] Guidance Document for Rapid Ohia Death - USDA Forest Service
Dec 1, 2016 · fimbriata strain genetically distinct from the pathogen attacking 'ōhi'a in Hawai'i was first detected on dying non-native Eucalyptus (Myrtaceae ...Missing: timeline | Show results with:timeline
[88]
05/24/22 – IT'S OFFICIAL! ʻŌHIʻA LEHUA BECOMES HAWAI'I ...
May 24, 2022 · As a keystone species it makes up fully 80% of our native forests. ... ecological, and economic importance and threats to the ʻōhiʻa lehua.Missing: functions | Show results with:functions
[89]
H.R. 1726, Continued Rapid Ohia Death Response Act of 2023
Jul 31, 2023 · The bill would require the Forest Service to provide financial assistance to prevent the spread of ROD, restore native Hawaiian forests, and conduct ROD ...Missing: measures | Show results with:measures
[90]
ʻŌhiʻa Disease Resistance Program
The ʻŌhi'a Disease Resistance Program (ODRP) was established in 2018 to identify ROD-resistant ʻōhiʻa with the goal of producing disease-resistant plants.Missing: excluding | Show results with:excluding
[91]
ʻŌhiʻa Disease Resistance Program - | Tropical HTIRC
The ʻŌhiʻa Disease Resistance Program aims to develop ROD-resistant ʻōhiʻa trees for reforestation, identifying resistant trees and screening seedlings.
[92]
A framework for establishing a rapid 'Ōhi'a death resistance program
Jan 25, 2022 · We outline a framework for guiding the ʻŌDRP throughout the process of identifying and developing ROD resistance in M. polymorpha and, possibly, all Hawaiian ...
[93]
A framework for establishing a rapid 'Ōhi'a death resistance program
Jan 25, 2022 · We outline a framework for guiding the ʻŌDRP throughout the process of identifying and developing ROD resistance in M. polymorpha and, possibly, all Hawaiian ...
[94]
Striving Towards an Operational Disease Resistance Program for ...
Nov 27, 2024 · These surviving ʻōhiʻa will be planted on high ROD hazard sites to assess long-term survival and potential breeding efforts. Our findings ...
[95]
Screening of Metrosideros polymorpha ('ōhi'a) varieties for ...
Nov 26, 2020 · The results of this preliminary study suggest that some form of resistance might be present in natural populations of at least one variety of M.
[96]
Key to unlock solution for rapid ʻōhiʻa death could be in seeds of ...
Jul 10, 2025 · The ʻŌhiʻa Disease Resistance Program was established in 2018 to explore whether some ʻōhiʻa in high-mortality areas randomly escape ...Missing: lehua | Show results with:lehua
[97]
Disease Could Kill Most of The Big Island's 'Ohi'a Forests Within 20 ...
Nov 13, 2024 · ... genetically the most resistant to the fungus. That effort by the Rapid ʻOhiʻa Death Resistance Program is a decades-long project because it ...
[98]
7/22/24 – TEN YEARS OF FIGHTING RAPID OHIA DEATH
Jul 23, 2024 · For immediate release July 22, 2024, ten years of fighting Rapid ʻŌhiʻa death and the search for solutions continues.
[99]
S.85 - Continued Rapid Ohia Death Response Act of 2025
This bill establishes requirements to research and control the fungus Ceratocystis, known as Rapid Ohia Death, which has killed more than a million native trees ...
[100]
Continued Rapid Ohia Death Response Act of 2025 - Congress.gov
An Act to require the Secretary of the Interior to partner and collaborate with the Secretary of Agriculture and the State of Hawaii to address Rapid Ohia ...<|control11|><|separator|>
[101]
Tokuda bill would increase support to combat rapid ohia death
Oct 1, 2024 · A bill that would significantly boost the state's efforts to combat rapid ohia death passed the U.S. House of Representatives last week.
[102]
MISC: ʻŌhiʻa seeds from resilient trees may hold the key to ...
Jul 7, 2025 · Rapid ʻŌhiʻa Death (ROD) was detected in three landscaped ʻōhiʻa trees in Central Maui in February. ROD is a fungal disease that can kill a ...Missing: timeline | Show results with:timeline
[103]
Tropical Plant Genetic Resources and Disease Research: Hilo, HI
The objectives of the project are to provide Rapid Ohia Death (ROD) testing capacity, collect lab, greenhouse and field data, isolate ROD fungi from high ...
[104]
[PDF] ʻŌhiʻa Forest Futures: Research for Resilience and Restoration
Aug 26, 2024 · ʻŌhiʻa lehua (Metrosideros polymorpha) is Hawaii's most important native tree. It covers nearly one million acres and is deeply intertwined ...
[105]
`ŌHI`A LEHUA (METROSIDEROS POLYMORPHA) | Hawaiian Rain ...
Mar 24, 2014 · TRADITIONAL HAWAIIAN USES. very hard wood with a variety of uses, among them images of the gods (ki`i), posts and beams for hale and heiau ...
[106]
The cultural significance of ohia lehua - Hawaii Magazine
Apr 12, 2016 · As such, the abundant plant had many uses for early Hawaiians: Ohia's sturdy wood was used to create weapons, kapa cloth beaters, boards for ...Missing: applications | Show results with:applications
[107]
5 Things You Need to Know About the ʻŌhiʻa Lehua Tree
Apr 23, 2021 · One of Hawaiʻi's most iconic tree, the ʻōhiʻa lehua (Metrosideros polymorpha) is endemic to the Hawaiian Islands and is steeped in the Islands' history.
[108]
'Ōhi'a - Uses - Ulana | Hilo, Hawaii
The ʻōhiʻa apane (very dark red lehua) is used as medicine during childbirth, while the young leaves of the ʻōhiʻa are used to treat pale babies.
[109]
Ohia | The Wood Database (Hardwood)
Ohia, scientifically Metrosideros spp., is a Pacific island wood, 65-100 ft tall, with reddish-brown heartwood, and is used for furniture and flooring. It is ...
[110]
ʻŌhiʻa lehua (Metrosideros polymorpha) - Kalama Hardwoods
It is one of the trees initially used by native Hawaiians for critical construction applications such as tools, and wear-strips along the gunwales of canoes.<|separator|>
[111]
Rapid Ohia Death > THE DISEASE > MORE ABOUT 'OHI'A - CTAHR
Overview of the importance of ʻōhiʻa, Metrosideros polymorpha, to Hawaiian economy, ecosystem and culture.
[112]
ʻŌhiʻa (U.S. National Park Service)
Nov 2, 2021 · ʻŌhiʻa was already in love with a woman named Lehua, however. In an act of wild jealousy, Pele transformed him into a gnarled tree. Pele refused ...
[113]
Cultural Significance - Maui Forest Bird Recovery Project
... (Metrosideros polymorpha). The ancient Hawaiians sometimes chanted about the 'Apapane bird and other honeycreepers. In the Kumulipo, the Hawaiian creation ...
[114]
ʻŌHIʻA LEHUA - ScholarSpace
ABSTRACTFor my MFA Dance (Performance and Choreography) Thesis, I created, directed, and choreographed a work of performance art entitled ʻŌhiʻa Lehua.
[115]
Kamehameha School juniors bring new mele of cherished ohia ...
Mar 3, 2020 · Inaba is in a cohort of students that composed a song about rapid ohia death that will be performed by the junior class at the 100th annual Kamehameha Schools ...Missing: modern | Show results with:modern
[116]
Poetry for the ʻōhiʻa tree (2) - The Hawaii Independent
Mar 11, 2016 · ʻŌhiʻa and Lehua are dying. Devastated by natural disasters and human destruction. Their seeds are no longer fruitful. They are fighting to stay ...