Elateriospermum tapos Blume, Bijdr. 621 (1826)
Species named after the local Sundanese name.
Elateriospermum rhizophorum Boerl. & Koord.
Tree with white to yellowish, sticky latex. Vegetative parts glabrous. Stipules present. Petioles
clearly swollen at base and top. Leaves alternate in whorls, young leaves bright red, upper leaf
with two basal glands. Branched inflorescences with white-yellowis male flowers, female flowers
greenish. Fruits a large capsule, splitting open when ripe.
Tree, up to 27(-50) m high, dbh up to 56 cm, bole up to 10 m high, sometimes shortly fluted or
with buttresses up to 2 m high, 1.2 m wide and 15 cm thick; crown deeply conical, hemispherical,
multilayered, monopodial. Outer bark dirty white to (grey-)brown, c. 1 mm thick, hard, smooth to
finely fissured and slightly scaly with c. 1.5 cm long flakes; inner bark red to pale brownish to
partly pale yellowish, c. 10 mm thick, glabrous, firm; sapwood white to light yellow; heartwood
dark brown. Stipules triangular, 2-3 mm long. Leaves: petiole 1-8 cm long, flat or somewhat hollow
adaxially; blade elliptic to obovate, 5-24 by 2-7.5 cm, length/width ratio 2.5-3.2, base obtuse to
cuneate, apex abruptly acuminate to cuspidate, upper and lower surface smooth, dark green above,
paler beneath; venation raised especially below, nerves 7-17 per side, looped and closed near the
margin. Inflorescences up to 19 cm long, hairy, cymules 0.5-6 cm long, bracts triangular, 1-1.4 by
0.7-1 mm, peduncle 2-9 cm long. Flowers white to pale yellow, fragrant with unpleasant scent; buds
white. Staminate flowers 2.4-3.5 mm diam.; pedicel 2-7 mm long, hairy; sepals ovate, 2.5-6 by
2.2-5 mm, apex rounded, puberulous outside, glabrescent; disc 0.8-1.3 mm high; stamens yellow,
filaments 0.3-2 mm long, orange at base, anthers 0.8-1.2 by 0.2-0.4 mm. Pistillate flowers
3.2-5.3 mm diam.; pedicel 1.3-4.2(-50 in fruit) mm long, hairy; sepals ovate, 4.5-8 by 3.2-5.5 mm;
disc 1-1.3 mm high; ovary ovoid, 2.5-4 by 2-2.6 mm, densely hairy, light green; style and stigma
thick, 0.3-0.5 mm long. Fruits oblong-ellipsoid, longitudinally 3-grooved, 3.2-5.3 by 2.2-4.5 cm,
glabrous, exocarp changing from green via red to turning dark brown (to black), endocarp yellowish.
Seeds 3.2-3.6 by 1.4-2.2 cm, brown-grey to dark brown, smooth. [from Flora Malesiana]
In hilly primary (mixed dipterocarp) and secondary forest, kerangas forest, forest edges, along
logging roads; soil usually deep and yellow-coloured, mainly clay, clay-loam, sandy clay, loam,
sometimes sandstone or (silty) laterite. Altitude: sea level up to 600 m. The flowers are visited
by dammar bees.
A tree of ornamental value. Its flowering indicates the start of the rice season. The seeds are
mainly used, but they are usually poisonous (cyanide) when fresh (though a few races are without
cyanide). The seeds can be eaten cooked or roasted, but too much may cause dizziness. On Sumatra
a paste is made of the seeds (pounded with some water) and used to flavour some kinds of sambal;
jungle tribes (Sakai) in Malaysia bury the paste packed in a bag or in bamboo in wet earth for a
month or more, the result is a fermented paste with a strong flavour, which is highly appreciated
with meals. The fermented paste is also used as fish bait. The oil is seldom pressed from the seeds,
pale yellow, nearly odourless and with a nice taste, to be used for cooking or as lamp oil. The
wood is usually considered as excellent. The sapwood is white, the heartwood with beautiful dark
brown flames. However, it is mainly used as firewood or for small items like handles of rubber
tapping knives, because it takes a nice polish. It could have been a good construction timber,
but only the sapwood is durable, the heartwood rots easily or is attacked by termites unless
treated with preservatives. The seeds make nice toys for children, they are used as toy beetles
or threaded together in a game called ¡®conquerors¡¯. The latex is used on Sumatra to shield dirty
wounds, because it dries quickly; the Bidayuh in Sarawak apply fresh latex once per day to crack
wounds on the soles of their bare feet. The latex is also used to polish blowpipes to a glossy
dark sheen (Malay Peninsula).
Peninsular Thailand and Malaysia, Sumatra, Java and Borneo.
Borneo: Bramban; kelampai (Iban-Sarawak); layang layang; paha; perah, perah ikan (Malay); rampeh,
Java: Tap(p)os (Sundanese).
Malay Peninsula: (Buah) perah, perah kokong; gua pra, ple prah (Sakai); piah, suing (Semang).
Sumatra: Asiloem (Karo); daun tepoes, kajoe si marsang-sang, kedoei, tapoes.
Thailand: Kra, pra (Thai); pi-ra (Bidayuh-Malay).