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Cyrtandra obliquifolia K.R. Wood & W.L. Wagner (Gesneriaceae), a new shrub species known only from Kaua'i, Hawaiian Islands, is described and illustrated with notes on its distribution, ecology, and conservation status. The new species is morphologically most similar to Cyrtandra wawrae C.B. Clarke but differs by its unique combination of oblique, non-peltate, auriculate leaf bases, more deeply divided calyx lobes, inflorescence with fewer flowers and lacking profusely umbellate cymes. Cyrtandra obliquifolia is known from only two localities which have undergone severe habitat degradation from landslides and invasive plants and animals and is determined to be Critically Endangered (CR) when evaluated under IUCN criteria. [ABSTRACT FROM AUTHOR]

The Hawaiian Islands are renowned for their exceptional biodiversity and are host to a plethora of endemic plant species, which have been utilized in traditional Hawaiian medicine. This scientific review provides an in-depth analysis of the phytochemistry and biological studies of selected endemic Hawaiian plants, highlighting their medicinal properties and therapeutic potential. A literature search was conducted, utilizing major academic databases such as SciFinder, Scopus, Web of Science, PubMed, Google Scholar, Science Direct, and the Scientific Information Database. The primary objective of this search was to identify relevant scholarly articles pertaining to the topic of the review, which focused on the phytochemistry and biological studies of endemic Hawaiian plants. Utilizing these databases, a comprehensive range of literature was obtained, facilitating a comprehensive examination of the subject matter. This review emphasizes the rich phytochemical diversity and biological activities found in Endemic Hawaiian plants, showcasing their potential as sources of novel therapeutic agents. Given the unique biodiversity of Hawaii and the cultural significance of these plants, continued scientific exploration, conservation, and sustainable utilization of these valuable resources is necessary to unlock the full potential of these plant species in drug discovery and natural product-based therapeutics. [ABSTRACT FROM AUTHOR]

Premise of research. The explosive diversification of Hawaiian Bidens is considered one of the premier examples of plant adaptive radiation in the native Hawaiian flora. Botanical exploration, especially in remote areas, continues and sometimes results in the discovery of new species. Most of these new discoveries are narrowly distributed endemics, and some are evaluated to be threatened or endangered, sometimes critically so, as is the case for Bidens wailele. Methodology. Bidens wailele K.R. Wood & Knope (Asteraceae/Compositae) is (1) described and illustrated from Kauai, Hawaiian Islands; we also (2) provide a diagnostic key distinguishing characters that separate B. wailele from all other native Kauai Bidens , (3) present a summary of its distribution, ecology, and threats; and (4) provide a formal Red List assessment utilizing the International Union for Conservation of Nature (IUCN) criteria for endangerment. This discovery is part of ongoing floristic research and exploration conducted by the National Tropical Botanical Garden Science and Conservation Department. Pivotal results. This new species occurs in extremely wet conditions around the waterfalls of Waialeale and Wainiha, central Kauai. Morphologically, it is most similar to Bidens valida , a Kauai endemic species naturally occurring around windswept ridges and cliffs of southeastern Kauai (as on Haupu, Hulua, and Kahili Mountains). Conclusions. This rare new species is presently known from only 700–800 individuals and restricted to three remote locations; B. wailele has been evaluated under the IUCN Red List criteria and proposed as critically endangered. A fourth population on a wet cliff where the new species historically occurred (i.e., Kamanu, Kauai) was destroyed by a landslide after its discovery in 2008, most likely caused by torrential rains and demonstrating the species' vulnerability for extinction. [ABSTRACT FROM AUTHOR]

Seven new species of endemic leaf-roller moths are described from the Hawaiian Islands: Eccoptocera hinanohomaunasp. nov. (O'ahu), Eccoptocera ohiaha, sp. nov. (O'ahu), Pararrhaptica kaiona, sp. nov. (O'ahu), Pararrhaptica pilikuanani, sp. nov. (Kaua'i), Spheterista huakunana, sp. nov. (O'ahu), Spheterista hiwakakahi, sp. nov. (Kaua'i), and Spheterista hakeaiki, sp. nov. (O'ahu). With the possible exception of S. hakeaiki, all species appear to be single-island endemics. In addition, Pararrhaptica pycnomias (Meyrick), syn. nov. (O'ahu), is treated as a junior synonym of Pararrhaptica notocosma (Meyrick) (O'ahu), Macraesthetica Meyrick is transferred from Eucosmini to Olethreutini, and Macraesthetica semicinereana (Swezey), comb. nov. (Hawai'i), is transferred from Nuritamburia Koçak & Kemal. A conservation status is proposed for each of the newly described species. [ABSTRACT FROM AUTHOR]

Molecular dating offers a tool for inferring the time of divergence between two lineages. In this study, we discuss how dated molecular reconstructions are informative of two different, albeit often intermingled, time estimates with regard to a fundamental process in island biogeography: the time of island colonization (TIC). We illustrate how stem age estimates provide information on the divergence between the extant island lineage and their closest relatives (i.e. the onset of lineage differentiation). Such estimates, however, are typically poor TIC predictors, as they are strongly affected by spatial and temporal uncertainty, particularly in cases of deep stem ages. Crown ages of endemic island lineages, in contrast, provide information on the temporal onset of island in situ diversification, and may represent a better proxy for TIC when the associated uncertainty is taken into account. Thus, the geographic and temporal distance separating the island and mainland lineages in phylogenetic/phylogeographic reconstructions are key factors for determining the reliability of these two estimates as proxies of TIC. We show how divergence times can be used to investigate the biogeographic patterns of two well-studied oceanic archipelagos: Hawaii and the Canary Islands. A compilation of molecular age estimates for nearly one-third of the endemic plant lineages in each archipelago reveals that Canarian plant lineages exhibit significantly younger mean crown ages (2.1 ± 2.4 Myr) than Hawaiian lineages (3.5 ± 2.9 Myr), despite island substrates being much older in the Canarian archipelago. We postulate that this pattern suggests: (1) a more important role of submerged islands during plant colonization in Hawaii, and (2) higher taxon turnover in the Canaries, mediated by relatively young (Mediterranean) lineages, and probably facilitated by the combination of the high incidence of extinction for the last 5 Myr and the close proximity of mainland source areas as compared to Hawaii. [ABSTRACT FROM AUTHOR]

The origins and evolution of Hawaiian biodiversity are a matter of controversy, and the mechanisms of lineage diversification for many organisms on this remote archipelago remain unclear. Here we focus on the poorly known endemic leaf-mining moth genus Philodoria (Lepidoptera, Gracillariidae), whose species feed on a diversity of Hawaiian plant lineages, many of which are critically endangered. We use anchored hybrid enrichment to assemble the first phylogenomic dataset (507 loci) for any Hawaiian animal taxon. To uncover the timing and pattern of diversification of these moths, we apply two frequently used dating calibration strategies, biogeographic calibrations and secondary calibrations. Island calibrations on their own resulted in much younger and unrealistic dates compared to strategies that relied on secondary calibrations. Philodoria probably originated on the now partially sunken islands of Laysan or Lisianski, approximately 21 Ma, and were associated with host plants in the families Ebenaceae, Malvaceae or Primulaceae. Major feeding groups associated with specific host-plant families originated soon after the plants colonized the islands. Allopatric isolation and host shifts, in concert and independently, probably play major roles in the diversification of Philodoria. Our dating results indicate that Philodoria is among the oldest known Hawaiian arthropod lineages, and that island calibrations alone can lead to unrealistically young dates. [ABSTRACT FROM AUTHOR]

Coprosma kawaikiniensis K.R. Wood, Lorence & Kiehn (Rubiaceae), a rare endemic tree from Kaua'i, Hawaiian Islands, is described and illustrated along with a previously undescribed endemic plant community, the Dubautia-Sadleria shrubland-fernland (DSSF). The new species differs from Hawai'i congeners by its combination of opposite, long, elliptic to narrowly elliptic or ovate-elliptic leaves with revolute margins; caducous stipules 7-10 mm long, externally glabrous, densely hirtellous-pilose near the margins of the inner surface; unbranched inflorescences with peduncles 20-28 mm long; flowers 6-8 per cluster; and persistent calyx tube with 4-8 irregular dentate lobes. Known only from the windward slopes and ridges of southeastern Kaua'i below the Kawaikini summit, Coprosma kawaikiniensis falls into the IUCN Critically Endangered (CR) Red List category. [ABSTRACT FROM AUTHOR]

More than one third of the USA's federally listed endangered and threatened plants are endemic to Hawaii. Because of the accelerating rate of environmental pressures resulting from habitat degradation to loss, the Hawaiian Rare Plant Program (HRPP, Lyon Arboretum, Honolulu, Hawaii) utilizes in vitro culture and seed storage to rescue, recover, and restore Hawaii's most critically endangered native plant taxa. These in vitro methods complement existing ex situ and in situ efforts in the state. Wild-collected seeds tend to be hard to clean, and obtaining contamination-free seeds or embryos without damage or over sterilization is one of the most difficult obstacles in the successful establishment of in vitro cultures. Loss of rare and valuable propagation material occurs when seed samples succumb to contamination or mortality during the initial disinfestation stage. This study reviews pre-treatments and provides examples of three general disinfestation protocols successfully used in the HRPP to establish axenic ovule and embryo cultures of some endangered Hawaiian species. Three disinfestation protocols are described: bleach sterilization, gas sterilization, and ethanol dip and flame. Since 1998, the HRPP has been successful in establishing in vitro cultures of 135 endangered Hawaiian plant taxa representing 30 genera. [ABSTRACT FROM AUTHOR]

Aim Pacific biogeographical patterns in the widespread plant genus Melicope J.R. Forst. & G. Forst. (Rutaceae) were examined by generating phylogenetic hypotheses based on chloroplast and nuclear ribosomal sequence data. The aims of the study were to identify the number of colonization events of Melicope to the Hawaiian Islands and to reveal the relationship of Hawaiian Melicope to the Hawaiian endemic genus Platydesma H. Mann. The ultimate goal was to determine if the Hawaiian Islands served as a source area for the colonization of Polynesia. Location Nineteen accessions were sampled in this study, namely eight Melicope species from the Hawaiian Islands, four from the Marquesas Islands, one species each from Tahiti, Australia and Lord Howe Island, two Australian outgroups and two species of the Hawaiian endemic genus Platydesma. To place our results in a broader context, 19 sequences obtained from GenBank were included in an additional analysis, including samples from Australia, Papua New Guinea, New Zealand, Southeast Polynesia and Asia. Methods DNA sequences were generated across 19 accessions for one nuclear ribosomal and three chloroplast gene regions. Maximum parsimony analyses were conducted on separate and combined data sets, and a maximum likelihood analysis was conducted on the combined nuclear ribosomal and chloroplast data set. A broader nuclear ribosomal maximum parsimony analysis using sequences obtained from GenBank was also performed. Geographic areas were mapped onto the combined chloroplast and nuclear ribosomal tree, as well as onto the broader tree, using the parsimony criterion to determine the dispersal patterns. Results Phylogenetic analyses revealed that Platydesma is nested within Melicope and is sister to the Hawaiian members of Melicope. The Hawaiian Melicope + Platydesma lineage was a result of a single colonization event, probably from the Austral region. Finally, Marquesan Melicope descended from at least one, and possibly two, colonization events from the Hawaiian Islands. Main conclusions These data demonstrate a shifting paradigm of Pacific oceanic island biogeography, in which the patterns of long-distance dispersal and colonization in the Pacific are more dynamic than previously thought, and suggest that the Hawaiian Islands may act as a stepping stone for dispersal throughout the Pacific. [ABSTRACT FROM AUTHOR]

This is the first report of a study devoted to the population genetics of speciation in the endemic Hawaiian plant genus Schiedea (Caryophyllaceae). Here, we report the estimates of DNA sequence diversity and divergence in a newly isolated nuclear gene from Maui and Oahu Schiedea globosa populations. Overall, the species-wide average heterozygosity per silent site is π = 0.3%. The silent DNA diversity on the older island of Oahu (π = 0.24%) is almost twice as high as on the younger Maui (π = 0.14%). Consistent with this, the haplotype phylogeny suggests a more recent origin of the Maui populations. There is no significant isolation between the two Maui populations (Fst = 0.027), while isolation between the two islands is high (Fst = 0.57, P<0.0001). Pairwise mismatch distributions suggest population growth approximately 660 and 310 thousand generations ago for the Oahu and the Maui populations, respectively, which may be the minimal age for these populations. This is consistent with a fairly neutral frequency spectrum (Tajima's D is 0.34 and -0.94 for the Oahu and the Maui populations, respectively), suggesting that both populations are sufficiently old to have recovered from any initial founder effects. Relatively high nuclear DNA diversity in the S. globosa populations illustrates the usefulness of a DNA sequence-based approach to the population genetics of island plant populations. [ABSTRACT FROM AUTHOR]

The Hawaiian flora, because of its great isolation, high levels of endemism, known lineages, and high rates of endangerment, offers unique opportunities to explore patterns of endangerment related to phylogeny, ecological and life history traits, and geographic patterns. Nine percent of the native flora of 1159 taxa are already extinct, and 52.5% are at risk (extinct, endangered, vulnerable, or rare). Risk is strongly associated with limited geographic distribution at several scales: endemic taxa (native only to the Hawaiian Islands) are at far greater risk than indigenous taxa (with both Hawaiian and extra-Hawaiian ranges); single-island endemics are more at risk than multi-island endemics; small islands have the highest proportion of endemic taxa at risk; and endemics with more limited habitat distributions (elevation, community type) are more at risk. Historic population density is a strong predictor of risk, and taxa with low historic population densities are at greatest risk with rapid anthropogenic changes. Among the major islands, Maui Nui has the highest percent of taxa that are extinct. Kaua'i has the lowest percent of extinct taxa and the highest proportion of single-island endemic taxa that are rare. Endemic taxa at risk are associated with distributions in shrublands, forests, bogs, and cliff habitats. Endemic taxa with distributions in low elevation dry habitats have the highest proportion of taxa at risk, but the greatest absolute numbers of taxa at risk have distributions in mesic lowland and montane forests, and in wet montane forests. The life history patterns associated with risk are complicated, and inclusion of the effects of evolutionary relationships (lineages) changes some of these patterns. Species level analyses without respect to lineage shows risk associated with monomorphic (hermaphroditic) breeding systems and bird pollination because of the large number of hermaphroditic, bird-pollinated species in the Campanulaceae. Analyses incorporating the effect of lineage greatly reduce the impact of large lineages and result in an association of risk with insect pollination, and no effect of breeding system. There is no association of lineage size and the percent of taxa at risk within the lineage; endemic taxa from lineages with large radiations are at no greater risk than endemic single-taxon lineages. The percentages of taxa at risk at the family level in the Hawaiian Islands and worldwide (excluding Hawaiian taxa) are positively correlated, although flowering plant families in the Hawaiian Islands have a much greater proportion of taxa at risk. Some of the approaches described here may be useful to predict geographical and biological patterns of endangerment in island and island-like ecosystems under increasing pressures of endangerment and extinction. [ABSTRACT FROM AUTHOR]