Gymnostoma sumatranum - Rhu Bukit

Synonym - Casuarina sumatrana.. .

Its native to tropical Asia, found in Malesia-Sumatra region. In Malaysia, it is known as Rhu Bukit. In Sarawak it is a protected species. It is official tree of Kota Kinabalu City Hall of Sabah.. .

Gymnostoma sumatranumis a family of Casuarinaceae, of order Fagales. Casuarinaceae consist of 3 or 4 genera and approximately 70 species of trees and shrubs native to the Old World tropics, Australia and the Pacific Island. At one time, all the species were places in the genus Casuarina, but are now split among Allcasuarina, Casuarina, Ceuthostoma and Gymnostoma.

.

Description

A moderately large tree, capable to grow up to 30 meter in heights. Twigs are evergreen, drooping equisetoid. Foliage is of multiple ronded umbrella shaped crowns. The roots have nitrogen fixing nodules that contain the soil actinomycetes Frankia. Stems are angular or tetrahedral in cross section. Female inflorescences are borne terminally . .

Propogation

G. sumatranum is propagated by seeds. Requires a well-drained medium. Germination in 30-90 days.

Propagation by rooting stem shows about 60 – 70 % of success with mature softwood stem cuttings. Rooted cuttings inoculated with Frankia were easily transplanted and established in field conditions with very low (about 3%) mortality. ⁽¹⁾. .

Economics

Its widely use as ornamental trees.

Produce superior quality charcoal in Sarawak. Annual commercial production is about 34,000 tons (weight) of firewood and 4,000 tons of charcoal. ⁽³⁾ . .

Reference

1.Goh C.J. et al, A Simple and Efficient Method of Clonal Propagation of Casuarina sumatrana, Plant Growh Regulation 17:115-120, 1995 (http://www.springerlink.com/content/t725m458205j1074/ )
2. Wikipedia ( http://en.wikipedia.org/wiki/Gymnostoma_sumatranum )
3. Innovations in Tropical Reforestation Casuarinas, nitrogen-fixing trees for adverse sites (http://nzdl.sadl.uleth.ca/cgi-bin/library.cgi?e=d-00000-00---off-0hdl--00-0----0-10-0---0---0direct-10---4-------0-1l--11-en-50---20-about---00-0-1-00-0-0-11-1-0utfZz-8-00&a=d&cl=CL2.18.5&d=HASH010c345e11867f606d9a3478.11)