Tetraplasandra racemosa

Common Name:
Munroidendron
(no Hawaiian name is known)

Classification:
Polyscias racemosa
Kingdom: Plantae-Plants
Subkingdom: Tracheobionta-Vascular plants
Superdivision: Spermatophyta-Seed plants
Division: Magnoliophyta-Flowering plants
Class: Magnoliopsida-Dicotyledons
Subclass: Rosidae
Order: Apiales
Family: Araliaceae - Ginseng family
Genus: Polyscias J. R. Forst. & G. Forst. - Polyscias
Species: Polyscias racemosa (Forbes) P. Lowry & G. Plunkett
(Lowry et al. 2010)

It has smooth, gray bark. The 12 inch long leaves are made up of many oval leaflets each of which is over 3 inches long. These trees drop most of their leaves during their summer blooming season. The small, pale yellow flowers hang in long, loose bunches.
(Wagner,W.L.,Herbst,D.R.,Sohmer,S.H. 1990. Manual of Flowering Plants of Hawai'i.)

It occurs naturally in only 3 locations on Kaua'i: Nounou Mountain, Na Pali cliffs, and Ha'upu Ridge near Nawilili Bay and Waimea Canyon.
(Wagner,W.L.,Herbst,D.R.,Sohmer,S.H. 1990. Manual of Flowering Plants of Hawai'i.)

Because each population of this species contains only a small number of trees, the species is threatened by extinction from naturally occurring events, such as landslides or hurricanes.(USFWS.2000.)

Other threats include habitat degradation by feral goats, fire, and fruit predation by rats.
In addition, a mature, cultivated tree was observed being killed by an introduced insect of the long-horned beetle family (Cerambycidae).This beetle could potentially attack and damage or kill wild trees(USFWS.2000.)

National Tropical Botanical Garden (NTBG) currently has ex situ holdings in its seed bank, which represents two out of the fifteen populations. In addition, there are approximately 400 plants growing in the nursery.
The Kaua'i District, Department of Land and Natural Resource, and the Department of Forestry and Wildlife outplanted approximately 400 individuals at Kauhao Ridge, and additional outplanting is planned. Other outplanting sites include: Sleeping Giant, DLNR Kalalau Exclosure, and Houpu.
The Lyon Arboretum, National Tropical Botanica Garden, and the Waimea Arboretum have successfully propagated Munroidendron racemosum.(USFWS.1995.)

Research Management Needs:
1. Fence and manage surviving wild populations of M. racemosum.
2. Test the influence of weeding and fencing on populations of Munroidendron racemosum.
3. Conduct pollination biology genetics and seed dispersal studies.

Ex Situ Needs:
1. Establish secure ex situ stocks with full founder representation.
2. Develop proper horticultural protocols and pest management for Munroidendron racemosum.
3. Survey ex situ holdings and conduct molecular fingerprinting of Polyscias racemosa.
(Recommendations derived from Chapin,M.H. and Maunder,M.)

The National Seed Storage Laboratory (NSSL) found inconclusive results after testing the seeds of Polyscias racemosa. The seeds are probably not tolerant to freezing. The laboratory germination time was 6 months.(Yoshinaga. 2002.)

Noted as an early conservationist and botanical explorer, especially on Lanai, Munro was manager of Molokai Ranch early in 20th century and was one of the first to find this plant. He was particularly famed as an ornithologist and was the author, in 1944, of the popular and beautifully illustrated Birds of Hawaii.
(Green,P.S. 1996. A Hawaiian Florilegium.)

This small tree has a strong, slender trunk and attractive flowers and foliage. It is unusual in appearance and works well as a specimen tree or for a background planting.