Polyscias racemosa

Life-forms

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Eudicots
Cladus: Core eudicots
Cladus: Asterids
Cladus: Campanulids
Ordo: Apiales

Familia: Araliaceae
Subfamilia: Aralioideae
Genus: Polyscias
Species: Polyscias racemosa
Name

Polyscias racemosa (C.N.Forbes) Lowry & G.M.Plunkett, Pl. Divers. Evol. 128: 74 (2010).
Synonyms

Munroidendron racemosum (C.N.Forbes) Sherff
Munroidendron racemosum var. forbesii Sherff
Munroidendron racemosum var. macdanielsii Sherff
Tetraplasandra racemosa C.N.Forbes

Continental: Pacific
Hawaii

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References

Lowry, P.P. & Plunkett, G.M., 2010. Pl. Divers. Evol. 128: 74

Links

Govaerts, R. et al. 2018. Polyscias racemosa in World Checklist of Selected Plant Families. The Board of Trustees of the Royal Botanic Gardens, Kew. Published online. Accessed: 2018 Nov. 23. Reference page.
International Plant Names Index. 2018. Polyscias racemosa. Published online. Accessed: Nov. 23 2018.
The Plant List 2013. Polyscias racemosa in The Plant List Version 1.1. Published online. Accessed: 2018 Nov. 23.
Tropicos.org 2018. Polyscias racemosa. Missouri Botanical Garden. Published online. Accessed: 23 Nov. 2018.

Vernacular names

Polyscias racemosa, or false 'ohe,[3] is a species of flowering plant in the family Araliaceae. As Munroidendron racemosum, the species was until recently considered to be the only species in the monotypic genus Munroidendron. With the change in classification, Munroidendron is now obsolete. Polyscias racemosa is endemic to the Hawaiian island of Kauai.[4] It is very rare in the wild and some of its original habitat has been replaced by sugar cane plantations.[5] It was thought for some time to be probably extinct, but was rediscovered a few years prior to 1967.[6]

Using cladistic methods, phylogenetic studies of DNA have shown that the closest relative of Munroidendron racemosum is Reynoldsia sandwicensis.[7] These two species are now known as Polyscias racemosa and Polyscias sandwicensis, respectively. They are two of the 21 species now placed in Polyscias subgenus Tetraplasandra.[8]

Polyscias racemosa is known in cultivation in Hawaii.[9] Cultivation procedures for Polyscias racemosa have been studied.[10]
Contents

1 Description
2 Habitat and range
3 History
4 References
5 External links

Description

Polyscias racemosa is a small tree growing to 25 ft (7.6 m) tall, with a straight trunk, spreading branches, and smooth, grey bark.[11] Like many members of Polyscias, it is sparingly branched and thick-stemmed, with large imparipinnate leaves, but not as extreme in these characteristics as is Polyscias nodosa.

Its leaves are pinnate, 12 in (30 cm) long, with oval leaflets, each of which is over 3 inches (7.6 cm) long. These trees are dry season deciduous, dropping most of their leaves during their summer blooming season. Its small, pale yellow flowers hang in long, rope-like strands.[12] The inflorescence is racemose in form, with up to 250 flowers.[13]

Flowers

Flowers
Inflorescence

Inflorescence
Leaves

Leaves
New Leaves

New Leaves

Habitat and range

Polyscias racemosa occurs in coastal mesic and mixed mesic forests at elevations of 120–400 m (390–1,310 ft), where it grows on exposed cliffs and ridges. Associated plant species include papala kepau (Pisonia umbellifera), ʻāwikiwiki (Canavalia galeata), ʻilima (Sida fallax), ʻōlulu (Brighamia insignis), alaheʻe (Psydrax odorata), kōpiko (Psychotria spp.), olopua (Nestegis sandwicensis), ʻahakea (Bobea timonioides), hala pepe (Pleomele aurea), and ʻālaʻa (Pouteria sandwicensis).[14] It occurs naturally in only three locations on Kauaʻi: Nounou Mountain, the cliffs of the Nā Pali Coast, and Haʻupu Ridge near Nāwiliwili Bay.
History

Polyscias racemosa first entered the botanical literature in 1917, when it was described and named as Tetraplasandra racemosa by Charles Noyes Forbes.[15]

Earl Edward Sherff felt that this species was uniquely distinct from the rest of Tetraplasandra, so he erected a new genus for it, Munroidendron, in 1952.[16] The genus was named for George Campbell Munro (1866-1963), described by Umberto Quattrocchi as "a pioneer in Hawaiian ornithology, botany, and horticulture; plant collector in the Hawaiian Islands".[17] Dendron is a Greek word for "tree". Munro was apparently the first collector to see his eponymous genus, Munroidendron.[18]

Sherff separated Munroidendron from Tetraplasandra on the basis of five characters: the absence of umbellules, the arrangement of the flowers in a raceme, the sunken, diamond-shaped pedicel scars, the long, persistence of the subtending floral bracts, and the insertion of the stamens in only one whorl, even when numerous.[18] It has been shown that, in spite of its appearance, the inflorescence is not truly a raceme because it is determinate.[11]

Sherff divided the species now known as Polyscias racemosa into three varieties: var. racemosa, var. forbesii, and var. macdanielsii. These have been described as "not sufficiently distinct to be retained".[11]

The establishment of Munroidendron was contentious from the beginning. William R. Philipson said that Munroidendron "comprises a single species with such a distinct inflorescence and corolla that it can well claim generic status.[19] In 1971, a pollen study indicated that Munroidendron might be embedded in Tetraplasandra.[20] This result was not supported by molecular phylogenetic studies based on DNA sequences of nuclear and chloroplast DNA regions.[7] These studies show that Polyscias sandwicensis (formerly Reynoldsia sandwicensis is not most closely related to other species of Reynoldsia, but is sister to Polyscias racemosa, (formerly Munroidendron).[21] This pair is then sister to a monophyletic Tetraplasandra in the sense of Philipson (1970).[19] This pair of species and the nine species formerly in Tetraplasandra form a clade and comprise all of the Hawaiian species of Polyscias.[21] The 11 species of this "Hawaiian clade" and 10 species from Malesia, Melanesia, and southern Polynesia constitute Polyscias subgenus Tetraplasandra.[8]
References

Adams, J.W.A. (2016). "Polyscias racemosa". IUCN Red List of Threatened Species. 2016: e.T34055A83787166. doi:10.2305/IUCN.UK.2016-2.RLTS.T34055A83787166.en. Retrieved 20 November 2021.
"Polyscias racemosa (C.N.Forbes) Lowry & G.M.Plunkett". World Checklist of Selected Plant Families (WCSP). Royal Botanic Gardens, Kew. Retrieved 3 April 2014 – via The Plant List.
USDA, NRCS (n.d.). "Munroidendron racemosum". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 14 July 2015.
David G. Frodin and Rafaël Govaerts. 2003. World Checklist and Bibliography of Araliaceae. Royal Botanic Gardens, Kew. ISBN 978-1-84246-048-1. (See External links below).
Earl Edward Sherff. 1956. "Some Recently Collected Dicotyledonous Hawaiian Island and Peruvian Plants". American Journal of Botany 43(7):475-478.
Benjamin C. Stone. 1967. "A review of the endemic genera of Hawaiian plants" Botanical Review (Lancaster) 33(3):216-259.
Gregory M. Plunkett and Porter P. Lowry II. 2010. "Paraphyly and polyphyly in Polyscias sensu lato: molecular evidence and the case for recircumscribing the "pinnate genera" of Araliaceae". Plant Diversity and Evolution (formerly Botanische Jahrbucher) 128(1-2):23-54. doi:10.1127/1869-6155/2010/0128-0002.
Porter P. Lowry II and Gregory M. Plunkett. 2010. "Recircumscription of Polyscias (Araliaceae) to include six related genera, with a new infrageneric classification and a synopsis of species". Plant Diversity and Evolution (formerly Botanische Jahrbucher) 128(1-2):55-84. doi:10.1127/1869-6155/2010/0128-0003. (See External links below).
Clyde T. Imada, George W. Staples, and Derral R. Herbst. undated. Annotated Checklist of Cultivated Plants of Hawai‘i. (See External links below).
Kerin E. Lilleeng-Rosenberger. 2005. Growing Hawaiʻi's Native Plants. Mutual Publishing. ISBN 978-1-56647-716-1
Warren L. Wagner, Derral R. Herbst, and Sy H. Sohmer. Manual of the Flowering Plants of Hawaii, Revised Edition, 1999. Bishop Museum Press: Hololulu
"Munroidendron racemosum". Hawaiian Native Plant Propagation Database. University of Hawaiʻi at Mānoa. Retrieved 2009-03-03.
Peter S. Green (author) and Mary Grierson (illustrator). 1996. A Hawaiian Florilegium: Botanical Portraits from Paradise. University of Hawaii Press: Honolulu, Hawaii. ISBN 978-0-915809-20-2.
"Munroidendron racemosum". CPC National Collection Plant Profiles. Center for Plant Conservation. 2008-07-22. Archived from the original on 2012-02-23. Retrieved 2009-11-14.
Charles Noyes Forbes. 1917. "New Hawaiian Plants.-VI." Occasional Papers of the Bernice Pauahi Bishop Museum 6(4):51. (See External links below).
Munroidendron in International Plant Names Index. (see External links below).
Umberto Quattrocchi. 2000. CRC World Dictionary of Plant Names, volume III. CRC Press: Baton Rouge, New York, London, Washington DC. ISBN 978-0-8493-2673-8 (vol. III). (see External links below).
Earl Edward Sherff. 1952. "Munroidendron, a new genus of Araliaceous trees from the island of Kauai". Botanical Leaflets 7(section V):21-24. published by the author.
William R. Philipson. 1970. "A redefinition of Gastonia and related genera (Araliaceae)". Blumea 18(2):497-505.
Charles C. Tseng. 1971. "Light and Scanning Electron Microscopic Studies on Pollen of Tetraplasandra (Araliaceae) and Relatives". American Journal of Botany 58(6):505-516.
Annemarie Costello and Timothy J. Motley. 2007. "Phylogenetics of the Tetraplasandra Group (Araliaceae) Inferred from ITS, 5S-NTS, and Morphology". Systematic Botany 32(2):464-477.