Tropical Plant Database - Plant Details

Myoporum sandwicense, commonly known as Naio, is a shrub or small tree that grows from 1 to 10 m tall. Naio plants can be low-growing and widely spreading in form or multi-branched and erect shrubs. The slightly fleshy leaves are arranged alternately along the stem, are covered with glandular dots, and young leaves may be slightly sticky when young. The leaves are variable in shape reaching 2.5-22 cm in length and 0.5-4 cm in width. The white to pink Naio flowers are produced in small clusters containing 3-10 flowers in the leaf axils. The flowers are bell-shaped; the petals are fused at the base to form a short tube (4.5-12 mm long) and have five, triangular lobes that spread widely. A yellow nectary disc is present in the center of the flower and the inner surfaces of the petals may be covered with small white hairs. The fruit is 9 mm in diameter and is fleshy and round when young and dries somewhat and becomes ribbed as it matures. Each fruit contains a single, spindle shaped seed that is 2.5 mm long.

(Wagner, W. L., Herbst, D. R., and S. H. Sohmer. 1999. Manual of the Flowering Plants of Hawai‘i. Revised Edition. Volume 1. Bishop Museum Special Publication 97. University of Hawai`i Press, Bishop Museum Press, Honolulu, Hawai’i.)

Myoporum laetum from New Zealand produces photosensitization and liver damage in livestock that graze the plant. This species contains a toxic compound called ngaione in the volatile oils in the plant. Cattle and sheep that have consumed plant material may develop photodermatitis on the face, ears, eyes, and lips and large quantities may prove fatal to some animals.

(Schmidt, R.J. 2007. Myoporaceae. Botanical Dermatology Database. Accessed online on 9 August 2007 at http://bodd.cardiff.ac.uk/BotDermFolder/BotDermM/MYOP.html.)

Naio is a dominant species in dry subalpine Naio-Mamane (Sophora chrysophylla) woodland on Hawaii Island. Forest on Mauna Kea was studied from 1973-1975 to investigate possible change in the forest composition due to human influences including the introduction of feral ungulates. In the study area Naio is becoming increasingly common. Naio is not a preferred browse species for sheep and therefore experiences lower grazing pressure than Mamane, which may partially explain the change in abundance of the two species. Additionally, in the absence or reduction of native bird dispersers, non-native birds including the House finch (Carpodacus mexicanus), and the Red-billed Leiothrix (Leiothrix lutea) may more effectively contribute to seed dispersal of Naio than to that of Mamane.

(van Riper III, C. 1980. The phenology of the dryland forest of Mauna Kea, Hawaii, and the impact of recent environmental perturbations. Biotropica 12(4): 282-291.)

The trunks of Naio were traditionally used for the larger posts of hale and the smaller branches were used along the length of the roof to attach the thatching material obtained from Pili grass (Heteropogon contortus). The wood of Naio is fragrant when dried or burnt and smells similar to Sandalwood (Santalum sp.). During the nineteenth century when Sandalwood was exported from Hawai‘i Naio wood was used as a substitute when supplies of this wood became scarce due to overharvesting.

(Abbott, I A. 1992. La‘au Hawai‘i: Traditional Hawaiian Uses of Plants. Bishop Museum Press, Honolulu, Hawai’i.)

Naio is native to Hawai‘i where it is found on all the main islands from sea level to 2380m. It is found in a range of vegetation types including coastal strand vegetation, ‘a‘a lava fields, dry forest, mesic to wet forest, and subalpine forest. The genus Myoporum contains 28-30 species with a distribution in Asia, Australia, Mauritius, New Guinea, New Zealand, and the Pacific.

(Wagner, W. L., Herbst, D. R., and S. H. Sohmer. 1999. Manual of the Flowering Plants of Hawai‘i. Revised Edition. Volume 1. Bishop Museum Special Publication 97. University of Hawai`i Press, Bishop Museum Press, Honolulu, Hawai’i.)

The endangered bird species the Palila (Loxioides bailleui) is found in dry subalpine Naio-Mamane (Sophora chrysophylla) woodland on Mauna Kea on Hawai‘i Island. These woodlands provides 5% canopy cover to 10 m in height that is suitable for Palila as these birds nest at an average height of 5.2 m in patches with intact canopy. The birds prefer intact woodland with a high proportion of native plants in the understory. They forage on Naio flowers and berries and the leaf and flower buds and flowers of Mamane. Populations of Palila are currently threatened by limited food availability, habitat modification and loss, thermal stress, and possibly avian malaria and pox. The loss of intact subalpine woodland vegetation through herbivory in the understory by feral ungulates, erosion, and fire has greatly reduced available habitat for the Palili.

(U.S. Fish and Wildlife Service. 1986. Revised Palila Recovery Plan. U.S. Fish and Wildlife Service, Portland, OR. 49 pp.)

The name Myoporum is derived from the Greek words myo meaning close and poros meaning pore which describes the dense arrangement of the glands on the leaves of Naio plants.

(Wagner, W. L., Herbst, D. R., and S. H. Sohmer. 1999. Manual of the Flowering Plants of Hawai’i. Revised Edition. Volume 1. Bishop Museum Special Publication 97. University of Hawai`i Press, Bishop Museum Press, Honolulu, Hawai’i.)

Myoporum was previously classified in the Myoporum family (Myoporaceae) however recent study based on DNA sequence data and morphology have resulted in the inclusion of Myoporum in the tribe Myoporeae in the Scrophulariaceae family. This tribe includes six other genera (Androya, Bontia, Eremophila, Pholidia, Pholidiopsis, and Stenochilus).

(Olmstead, R.G., C.W. dePamphilis, A.D. Wolfe, N.D. Young, W.J. Elisons, and P. A. Reeves, 2001. Disintegration of the Scrophulariaceae. American Journal of Botany 88(2): 358261.)
(USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN) [Online Database]. National Germplasm Resources Laboratory, Beltsville, Maryland. Accessed on line on 9 August, 2007 at URL: http://www.ars-grin.gov/cgi-bin/npgs/html/.)

We currently have 65 herbarium specimens for Myoporum sandwicense in our collection. Click on any specimen below to view the herbarium sheet data.

• 036947 - collected by Harold St. John in 1931
• 033757 - collected by Harold St. John in 1946
• 033758 - collected by Harold St. John in 1946
• 036418 - collected by Harold St. John in 1946
• 037124 - collected by Harold St. John in 1947
• 036605 - collected by Harold St. John in 1948
• 036086 - collected by Harold St. John in 1950
• 016460 - collected by Derral Herbst in 1971
• 036592 - collected by Harold St. John in 1973
• 068197 - collected by Carolyn Corn in 1977
• 068196 - collected by J. Davis in 1982
• 018242 - collected by Art Medeiros in 1982
• 059770 - collected by Art Whistler in 1985
• 059769 - collected by Art Whistler in 1985
• 036361 - collected by Steve Perlman in 1992
• 036375 - collected by J. Regalado in 1993
• 017989 - collected by K. R. Wood in 1995
• 033756 - collected by K. R. Wood in 1996
• 028847 - collected by Steve Perlman in 1998
• 028620 - collected by David H. Lorence in 1998
• S062617 - collected by David H. Lorence in 1998
• 043796 - collected by Liloa Dunn in 1998
• 033385 - collected by K. R. Wood in 1999
• 038909 - collected by Steve Perlman in 2000
• 038924 - collected by Steve Perlman in 2000
• 038910 - collected by Steve Perlman in 2000
• 034202 - collected by Steve Perlman in 2000
• 041490 - collected by Tim Flynn in 2002
• 048015 - collected by K. R. Wood in 2005
• 058165 - collected by Natalia Tangalin in 2005
• 050632 - collected by Pat Conant in 2009
• 072750 - collected by Natalia Tangalin in 2009
• 072734 - collected by Natalia Tangalin in 2009
• 064870 - collected by Steve Perlman in 2011
• 065860 - collected by Natalia Tangalin in 2011
• 056128 - collected by David H. Lorence in 2011
• 070576 - collected by Natalia Tangalin in 2012
• 063080 - collected by K. R. Wood in 2012
• 063656 - collected by Tim Flynn in 2012
• S063854 - collected by Tim Flynn in 2012
• 082474 - collected by Jason T. Cantley in 2012
• 082475 - collected by Jason T. Cantley in 2012
• 065478 - collected by K. R. Wood in 2013
• 065410 - collected by K. R. Wood in 2013
• 070606 - collected by Natalia Tangalin in 2013
• 066922 - collected by Hank Oppenheimer in 2013
• Unassigned - collected by Tim Flynn in 2013
• 068079 - collected by Hank Oppenheimer in 2013
• 085032 - collected by K. R. Wood in 2014
• 085072 - collected by K. R. Wood in 2015
• 085252 - collected by K. R. Wood in 2015
• 075975 - collected by David H. Lorence in 2015
• Unassigned - collected by Natalia Tangalin in 2015
• 071276 - collected by K. R. Wood in 2015
• 071486 - collected by Seana Walsh in 2016
• 075918 - collected by K. R. Wood in 2016
• 076332 - collected by Katherine Brainard in 2017
• 076330 - collected by Katherine Brainard in 2017
• 076322 - collected by Katherine Brainard in 2017
• 076323 - collected by Katherine Brainard in 2017
• 076324 - collected by Katherine Brainard in 2017
• 077406 - collected by Tim Flynn in 2018
• 077403 - collected by Dustin Wolkis in 2018
• 080340 - collected by Barbara Kennedy in 2018
• 083423 - collected by Seana Walsh in 2020