Buxus rolfei (PROSEA)
Buxus rolfei S. Vidal
- Protologue: Revis. pl. vasc. filip.: 233 (1886).
- Family: Buxaceae
- Chromosome number: 2n= unknown
- Philippines: malagaap, piukbanau (Tagalog), sarapuyau (Negrito).
Origin and geographic distribution
B. rolfei is endemic to the Philippines (Luzon, Sibuyan, Palawan, Mindanao), but may possibly have been recorded from Sulawesi (Indonesia).
The fruits are dried and finely cut, and then scattered on water as a fish poison.
Leaves of B. harlandii Hance are used in Vietnam to treat dog bites.
Steroidal alkaloids of the 9β,19 cyclopregnane and 9(1019) abeo pregnane type have been found in all Buxus species investigated. Several of these isolated from the leaves of B. longifolia Boiss. and B. sempervirens L. showed significant antibacterial activity, also against human pathogenic bacteria. Furthermore, the steroidal alkaloid cyclobuxine isolated from B. microphylla Sieb. & Zucc. in Korea is reported to protect the isolated rat heart from the myocardial injuries produced by ischaemia and subsequent reperfusion by significantly suppressing ultrastructural damage. Buxaminol E isolated from the European B. sempervirens showed a hypotensive effect in tests with cats.
A glabrous shrub with compressed-tetragonal branches. Leaves opposite, simple and entire, elliptical to oblong, 5-17 cm × 1.5-8 cm, acute at base, shortly acuminate at apex, thinly leathery, with numerous distinct secondary veins connecting into an intramarginal vein; petiole 2-7 mm long; stipules absent. Inflorescence an axillary raceme with c. 5 pairs of bracts. Flowers unisexual; male flowers pedicelled, with 4 perianth segments and 4 stamens; female flowers terminal in inflorescence, without perianth but with c. 6 spirally arranged bracteoles, ovary superior, 3-celled, styles 3, short, persistent. Fruit an ovoid capsule 1-1.5 cm long, 3-celled with 2 seeds per cell. Seeds trigonous-ellipsoid, c. 7 mm long, shiny black.
Buxus consists of approximately 100 species. It has a centre of diversity (section Tricera ) in the Caribbean-Latin America region with about 50 species, more than 30 of which are confined to Cuba. A second centre of diversity is in eastern Asia, where about 40 species occur from China, Korea and Japan to Malaysia, Indonesia and the Philippines; most of these species have been classified in section Buxus , but 6 in section Eugeniobuxus (including B. rolfei ). In Africa, about 7 species have been found (section Probuxus ), whereas the 4 species of the closely related genus Notobuxus also occur here. Two species occur in Europe.
B. rolfei occurs in primary forest at low and medium altitudes.
B. rolfei appears to be endemic to the Philippines where it is restricted to primary forest, which is under high pressure. Consequently, it seems liable to genetic erosion and may become easily endangered.
The steroidal alkaloids present in Buxus are pharmacologically interesting compounds, which are probably also present in B. rolfei . This might offer possibilities for research.
117, 323, 495.
Other selected sources
55, 57, 121, 521, 535.
Main genus page