National Tropical Botanical Garden Research Articles

Gardenia (Rubiaceae) seed conservation physiology with emphasis on rare Hawaiian species

Background and aims – Gardenia species are ecologically, culturally, and economically significant but the three native species of Gardenia in Hawai‘i are assessed as Critically Endangered. Seed banking is the most cost effective and efficient means of conserving plant material ex situ. To better understand the conservation physiology of Hawaiian and South Pacific Gardenia spp. and support their conservation, we asked 1) How do seeds respond to different temperatures and light and dark regimes? 2) What class of dormancy, if any, do seeds exhibit? 3) How does seed germinability respond over time in a seed bank? and 4) What is the conservation status and level of ex situ representation of Gardenia globally? Material and methods – To answer these questions, we used 19 accessions of fresh seeds and seeds stored for varying periods of time in the National Tropical Botanical Garden’s Conservation Seed Bank and Laboratory of Hawaiian (G. brighamii, G. remyi), New Caledonian (G. aubryi, G. oudiepe), and Tahitian (G. taitensis) species. Seeds were incubated at varying temperatures and in light, and in dark. Key results – We found that (1) seeds of all species tested germinated slowly and only at higher temperatures in the light and dark, (2) seeds have non-deep physiological dormancy, (3) seeds of the Hawaiian species are short lived at conventional seed bank conditions, and (4) only 40% of Gardenia spp. are represented in ex situ facilities, and 66% of the species have not been evaluated for the IUCN Red List. Conclusion – Seeds of Hawaiian Gardenia spp. are short lived in storage. Since seeds germinate in darkness, they are unlikely to form a persistent soil seedbank. Although seeds of all species tested are physiologically dormant, they can be easily propagated from seed at warmer temperatures, giving some hope to the conservation and restoration of the Critically Endangered Hawaiian species. Since our dataset was limited by a lack of continuous viability monitoring, we emphasize the need for initial germination testing and ongoing viability tests to better understand seed longevity. Lastly, we discuss the ecological relevance of our results in the context of the Hawaiian archipelago.

Viability of ‘ōhai Sesbania tomentosa seeds after 3 decades of ambient conditions

Abstract The plant species Sesbania tomentosa (‘ōhai; Fabaceae) is endemic to the Hawaiian Islands, federally listed as endangered in the USA and has been proposed for categorization as Vulnerable on the IUCN Red List. In 2021, c. 12,000 seeds from 12 seed lots collected during 1990–1992 from across the Hawaiian Islands were discovered in ambient herbarium conditions (55% relative humidity (RH) at 20 °C). International gene bank standards suggest drying seeds in equilibrium with 15% RH and stored at −18 °C. To investigate seed viability, we mechanically scarified then sowed 15 seeds from each accession at daily alternating regimes of 12 h light and 12 h dark at temperatures of 25/15 °C, respectively. Germination was observed after 7 days and ended after 34 days. Mean final germination was 88.9 ± SD 0.1% (range 73–100%). Each seed lot was accessioned into the National Tropical Botanical Garden's Seed Bank and Laboratory. In seeds with a water-impermeable seed coat (i.e. physical dormancy), such as S. tomentosa, seeds can desorb but not absorb water. Therefore, if the seeds were initially dried, although exposed to high RH for up to 32 years, seed equilibrium RH may have remained low, which may in part explain the observed high germinability. This study holds significance for managers who are working to conserve this endangered Hawaiian species and suggests that even suboptimal conditions may still yield highly viable seeds several decades into the future.

Bidens wailele (Asteraceae: Coreopsideae): A New Critically Endangered Species from Kauai, Hawaiian Islands

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.

Variation in Germination Traits Inform Conservation Planning of Hawaiʻi's Foundational ʻŌhiʻa Trees

ABSTRACT Climate can play a critical role in seed development and germination. Linking seed germination information with environmental variables and provenance may be important in understanding plant community structure and response to climate change, which can help guide conservation planning. Native Hawaiian Metrosideros (Myrtaceae; ʻŌhiʻa) is a hyperdiverse species complex that dominates Hawaiʻi's wet and mesic forests and serves as the most bioculturally important native plant in Hawaiʻi. In response to Rapid ʻŌhiʻa Death, a major threat to native forests caused by introduced fungal pathogens, seed collections of ʻŌhiʻa across the state have increased. We used initial seed germination data from recent collections stored in the National Tropical Botanical Garden’s Seed Bank to explore if seed germinability is correlated with seed zones and environmental variables. Linear models of the proportion of seed germinated, seed zones, and environmental data revealed that only seed zones were significantly correlated with the proportion germinated. Seed germination was lower for the “Nā Pali Valleys” than the “Windward Ranges.” Generalized provisional seed zones are a helpful tool for conservation collecting and restoration planning. Germination data routinely collected for seed bank collections provide an easily accessible source of preliminary information for these purposes.

Germination of seeds from herbarium specimens as a last conservation resort for resurrecting extinct or critically endangered Hawaiian plants

AbstractHistorical herbarium collections have been proposed as a last resort for recovery of extinct plant species not represented in dedicated seed banks or other living conservation collections. For critically endangered plants at the brink of extinction, herbarium collections may also contain historical material from extinct subpopulations representing a species' former range and lost genetic diversity of high value for conservation management. We explored the potential for germination of 81 critically endangered seed plant taxa endemic to the Hawaiian island of Kaua'i from herbarium specimens in herbarium PTBG of the National Tropical Botanical Garden (NTBG). Of 1250‐recorded specimens of wild origin, 138 specimens representing 37 taxa contained mature seeds that could be subjected to germination testing. Seven of these taxa were not represented by any NTBG seed bank collections. Fresh embryos were observed in one seed of each of the three species Schiedea helleri, Schiedea kauaiensis, and Viola helena. While potential germination success may be low, we conclude that testing of seeds from herbarium collections should be extended from a focus on strictly extinct taxa to critically endangered taxa, which may not have sufficient representation in seed banks or other living collections of subpopulations and genetic diversity across their wild range.

In remembrance of: Scott A. Mori (1941–2020), Tropical Botanist Extraordinaire

In remembrance of: Scott A. Mori (1941–2020), Tropical Botanist Extraordinaire

Pogostemon guamensis Lorence & W.L.Wagner (Lamiaceae), a new species from Guam, Mariana Islands.

While undertaking a botanical survey of the Andersen Air Force Base on Guam (Mariana Islands) in 1994, botanists from the National Tropical Botanical Garden collected an unusual suffrutescent, non-aromatic member of the Lamiaceae family growing on limestone cliffs in the northeastern part of the island. Based on morphology and molecular data (trnLF, matK), it was determined to belong to the genus Pogostemon Desf., a genus previously unknown from the Micronesian, Melanesian, and Polynesian region. Moreover, the analysis also showed that it was not conspecific with P. cablin (patchouli), and of the species available to include in the phylogenetic analyses it is sister to P. hirsutus¸ a species from India and Sri Lanka. Differing from its congeners by its large, loose inflorescence 2.5–5 cm wide and up to 7 cm wide in fruit, it is here illustrated and described as a new species, Pogostemon guamensis Lorence & W.L. Wagner and its habitat and conservation status are discussed.

Scott Alan Mori (1941—2020): An Appreciation

Scott Alan Mori (1941—2020) was among the most distinguished and prolific botanists in the 129-year history of The New York Botanical Garden (NYBG). He spent nearly 40 years of his career at NYBG before retiring in 2014 as Nathaniel Lord Britton Curator of Botany, and then serving as Curator Emeritus until his death on August 12, 2020. Over the course of his career he collected more than 27,000 herbarium specimens, described and named 125 new taxa, had at least 70 new taxa named in his honor, wrote more than 130 scientific papers and dozens of popular articles and blog posts, authored or edited 18 books or monographs, and was the major professor for 11 graduate students. His decades of professional accomplishments brought him many of the most prestigious awards in botany. He was awarded the Engler Medal in Silver from the International Association of Plant Taxonomy for the best publication in systematic botany in 2002. He received the David Fairchild Medal for Plant Exploration in 2007 from the National Tropical Botanical Garden. He won the Asa Gray Award in 2007 from the American Society of Plant Taxonomists. This article examines the multi-faceted legacy of Scott Mori as a great neotropical plant explorer, botanical scholar, author, educator, mentor, conservationist, colleague, and friend. This article also reviews the places that he visited, the projects on which he worked, and the people with whom he collaborated, with appreciative commentaries provided by some of the many individuals he profoundly influenced over the years.

LatinX botanical epistemologies

How is the field of Latina/o Studies concerning itself with “botanical epistemologies” in light of what scholar Claudia Milian has described as “environmental forecasts and new forms of LatinX displacements and transitions”? How have botanical epistemologies been associated with LatinX populations in the United States and its territories? How is the present-day “order of things” bringing social, economic, cultural, and ideological pressures to bear upon these epistemologies? As Chipper Wichman, Director of the National Tropical Botanical Garden, explains, “plants hold the answer to mitigating climate change, feeding the hungry, providing cures for diseases, and much more” and “80 percent or more of the planet’s biodiversity exists in the tropics and approximately one third of all tropical plants are threatened with extinction.” Plants provide living creatures with food and medicines and are responsible for producing the oxygen that makes life possible. However, “the loss of biodiversity-based cultural knowledge [of plants] is widely reported, globally as well as at the level of communities and individuals.” Specifically, LatinXs have not received credit for their botanical knowledge or its practices. This essay unearths how Latina/o Studies can help us to think through the relations among “LatinX,” botany, and the crossroads of survival and extinction—what the author proposes as “LatinX botanical epistemologies.”

A Landmark Publication for The South Pacific, Flora of The Cook Islands, Was Sponsored By The IAPT Book Publication Fund

TAXONVolume 66, Issue 2 p. 532-532 Plant Systematics WorldsFree Access A Landmark Publication for The South Pacific, Flora of The Cook Islands, Was Sponsored By The IAPT Book Publication Fund First published: 01 April 2017 https://doi.org/10.12705/662.31AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Literature Cited Funk, V.A., Susanna, A., Stuessy, T. & Bayer, R. 2009. Systematics, evolution, and biogeography of the Compositae. Vienna: IAPT. Sykes, W.R. 1970. Contributions to the flora of Niue. Bulletin, New Zealand Department of Scientific and Industrial Research 200. Wellington: DSIR. [Out of Print.] Sykes, W.R. 1977. Kermadec Islands flora: An annotated check list. New Zealand Department of Scientific and Industrial Research 219. Wellington: DSIR. [Out of Print.] Sykes, W.R. 2016. Flora of Cook Islands. Hawaii: National Tropical Botanical Garden. Volume66, Issue2April 2017Pages 532-532 ReferencesRelatedInformation

What to do when we can't bank on seeds: What botanic gardens can learn from the zoo community about conserving plants in living collections

What to do when we can't bank on seeds: What botanic gardens can learn from the zoo community about conserving plants in living collections

Agents of change

Sustainability in the face of climate change was the focus of a recent Smithsonian symposium celebrating the 50th anniversary of the National Tropical Botanical Garden.

Morphological diversity in breadfruit (Artocarpus, Moraceae): insights into domestication, conservation, and cultivar identification

Over millennia of breadfruit cultivation, hundreds of named cultivars have been developed that display a high degree of morphological diversity. The current study was undertaken to evaluate morphological diversity within the National Tropical Botanical Garden’s breadfruit germplasm collection, the largest and most diverse breadfruit collection in the world. A set of 57 standardized morphological descriptors including 29 leaf, 22 fruit, four seed, and two male inflorescence characteristics were used to describe and contrast 221 accessions of breadfruit including accessions of Artocarpus camansi Blanco, A. altilis (Parkinson) Fosberg, A. mariannensis Trecul, early generation A. altilis × A. mariannensis hybrids, and domesticated A. altilis × A. mariannensis hybrids. A morphological transition from heavily seeded fruit covered with flexible spines to fewer seeded, smoother skinned fruit of similar size was observed in the domestication of A. altilis from A. camansi. Further selection of true seedless, smooth-skinned cultivars of A. altilis appears to have occurred with human migrations from Melanesia into Polynesia. Cultivars from Micronesia exhibit morphological characteristics indicative of hybridization with the endemic species A. mariannensis. These data were used to generate a multi-access cultivar identification key on the Lucid platform that can be used to identify trees of known cultivars or to predict nearest cultivar relationships for previously undescribed cultivars. Overall, this study provides new insights into the morphological changes that occurred during domestication, helps visualize the diversity that exists across geographical regions, and provides a framework for cultivar identification and germplasm conservation.

Introduction to Botany of the Marquesas Islands: new taxa and combinations papers

Introduction to Botany of the Marquesas Islands: new taxa and combinations papers

Rediscovery, conservation status and taxonomic assessment of Melicope degeneri (Rutaceae), Kaua‘i, Hawai‘i

ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials ESR 14:61-68 (2011) - DOI: https://doi.org/10.3354/esr00345 Rediscovery, conservation status and taxonomic assessment of Melicope degeneri (Rutaceae), Kaua‘i, Hawai‘i Kenneth R. Wood* National Tropical Botanical Garden, Kala–heo, Hawai‘i 96741, USA *Email: kwood@ntbg.org ABSTRACT: Melicope degeneri (B. Stone) T. Hartley & B. Stone is endemic to the island of Kaua‘i and is one of Hawai‘i’s rare members of the Rutaceae. Rediscovered in 1993 after not being documented for 67 yr, it is currently known from only 22 individuals. Data concerning its morphology, distribution, and ecological preferences are presented in this paper in order to contribute to the Global Strategy for Plant Conservation (GSPC) goals and to assist biologists and land managers in monitoring and protecting this species from extinction. A formal IUCN assessment of the species has been completed and is reported here as Critically Endangered (CR B2ab(iii,v); D). KEY WORDS: Melicope degeneri · Rutaceae · Hawaiian Islands · Prevention of extinction · Distribution · Ecological preferences · IUCN Red List Category · Critically Endangered Full text in pdf format PreviousNextCite this article as: Wood KR (2011) Rediscovery, conservation status and taxonomic assessment of Melicope degeneri (Rutaceae), Kaua‘i, Hawai‘i. Endang Species Res 14:61-68. https://doi.org/10.3354/esr00345 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in ESR Vol. 14, No. 1. Online publication date: May 06, 2011 Print ISSN: 1863-5407; Online ISSN: 1613-4796 Copyright © 2011 Inter-Research.

Nutritional and morphological diversity of breadfruit ( Artocarpus, Moraceae): Identification of elite cultivars for food security

Breadfruit ( Artocarpus altilis) is an underutilized staple crop developed over thousands of years by the indigenous peoples of Oceania. The current study evaluated protein and mineral content, fruit morphology and flour production in 94 cultivars of breadfruit grown within a single location at the National Tropical Botanical Garden in Hawaii. Across the cultivars, fruit weight ranged from 0.47–3.54 kg, the edible portion of the fruit after seeds, skin and core were removed ranged from 0.30 to 3.11 kg and the average protein content varied from 2.7 to 6.2% by dry weight. Depending on the cultivar, the fruit contained on a dry weight basis 283–1491 μg/g Ca, 3.6–31 ng/g Co, 1.1–5.6 μg/g Cu, 6.2–21.2 μg/g Fe, 7.5–16.2 mg/g K, 630–2281 μg/g Mg, 70–843 μg/g Na, 846–2379 μg/g P, and 1.5–10.7 μg/g Zn, representing significantly more calcium, cobalt, iron, potassium, and magnesium, comparable phosphorous, and slightly lower manganese and zinc than refined wheat, rice and corn flours. Together, these data are indicative of the high degree of phenotypic diversity of cultivated varieties of breadfruit and the potential for identification of individual cultivars that are particularly good sources of mineral and protein nutrition.

A History of Hawaiian Plant Propagation

The National Tropical Botanical Garden (NTBG) has been a leader in the propagation and cultivation of rare native Hawaiian plants for several decades. The organisation’s work in rare plant conservation started primarily with field research and has evolved into a large-scale nursery operation. The NTBG now produces thousands of plants a year for ex situ conservation, garden collections and restoration projects. Here a number of Hawaiian species are reviewed, and appropriate propagation and cultural methods for each are discussed.

A History of Hawaiian Plant Propagation

The National Tropical Botanical Garden (NTBG) has been a leader in the propagation and cultivation of rare native Hawaiian plants for several decades. The organisation’s work in rare plant conservation started primarily with field research and has evolved into a large-scale nursery operation. The NTBG now produces thousands of plants a year for ex situ conservation, garden collections and restoration projects. Here a number of Hawaiian species are reviewed, and appropriate propagation and cultural methods for each are discussed.

Diversity of Breadfruit (Artocarpus altilis, Moraceae) Seasonality: A Resource for Year-Round Nutrition1

Diversity of Breadfruit (Artocarpus altilis, Moraceae) Seasonality: A Resource for Year-Round Nutrition. Breadfruit, Artocarpus altilis (Parkinson) Fosberg, is an important but underutilized staple crop cultivated throughout Oceania and much of the wet tropics. Indigenous peoples have selected and cultivated cultivars with different fruiting seasons to effectively extend fruit production for most of the year. In the present study, the seasonality of 219 breadfruit accessions originating from 17 Pacific island groups, the Seychelles, the Philippines, and Indonesia, and now growing in the National Tropical Botanical Garden’s (NTBG) Kahanu Garden, Hana, Hawaii, were evaluated. The predominant season of male flower production for most cultivars was from May to September, and fruit was produced most frequently between August and January. However, there were differences in the duration of the fruiting season from year to year and among cultivars. Over the 10-year period, 14 cultivars did not reliably produce fruit; most of this group were ‘ulu afa’ trees collected from Tokelau. About 24 cultivars exhibited very little seasonality and produced fruit throughout the year. The rest of the cultivars could be clustered into seasonality groups with characteristic fruiting patterns. Comparison of literature values indicates that unlike Hawaii, the breadfruit season in most locations begins around the date the sun reaches zenith prior to the summer months and extends throughout the summer months. Five cultivars asexually propagated from the NTBG collection growing in Kiribati (1°28′ N) exhibit similar fruiting patterns as in Hawaii, except that they begin 2–3 months earlier. These data predict that cultivars with complementary fruiting seasons in Hawaii may experience a temporal shift in their seasonality but will maintain their compatibility when cultivated in different locations and could enable year-round fruit production in many regions.

Are We Naïve to Think We Can Save Rare Plants from Extinction?

In places such as the Hawaiian Islands, where over half the native flora may be at risk of extinction in coming decades, the criticism is sometimes raised that the situation is so hopeless that the talents, energy and money of botanical gardens and other plant conservation organizations is largely wasted in trying to save these plants. Although stories of failure abound, it is important to recognize that considerable progress is being made. Organizations such as the National Tropical Botanical Garden (NTBG) have led the way in this eleventh-hour effort, not by naïvely pursuing failed strategies, nor by pulling back and only pursuing very limited goals, but by approaching the huge challenges with an energetic pioneering spirit. By taking an innovative comprehensive approach, dealing with the crisis at the level of ecosystems and plant communities rather than merely individual species, NTBG and other organizations are making progress on a broad front that integrates a range of scales and techniques and adapts to the shifting circumstances through careful monitoring and a spirit of optimism that is coupled with scientific scepticism.