Trees (or shrubs) up to 45 m high, girth up to 3 m, dbh up to 60 cm; buttresses usually absent or indistinct, up to 1.2 m long, c. 7.5 cm thick; flowering branches 1– 4 mm thick. Outer bark (smooth to) flaky, finely fissured, peeling off in 1– 2 cm wide strips, coarsely granular, white to brown-grey to reddish brown to deep purple-brown, up to 2 mm thick; inner hard, gritty, salmon to red to purplish brown, up to 1 cm thick; cambium white to pale yellow; sapwood white to yellow-brown, heartwood pale reddish brown. Stipules falcate, obovate, 3 – 6.5 by 0.6 – 2.2 mm, subglabrous to subsericeous. Leaves: petiole 3 –17 mm long, reniform in transverse section, with grooves across; blade ovate (to elliptic), 3.5 –18.5 by 1.5 – 8 cm, length / width ratio 1.8 – 3.5, very apex narrowly rounded to mucronulate, nerves 7– 9 per side. Inflorescences densely hirsute; bracts triangular, c. 0.8 by 1 mm. Flowers greenish yellow to white-yellow to yellow, slight- ly fragrant, sweet; pedicels woolly; sepals ovate to rounded, 1.5 – 3 by 1.5 – 3.3 mm; disc pink to red. Staminate flowers 2.2 – 3.7 mm diam.; pedicel 3.8 – 4.6 mm long; stamens: androphore 2.8 – 5 mm long, hairy, white, filaments 0.4 –1 mm long, anthers triangular to elliptic, 0.5 –1.2 by 0.4 – 0.6 mm, (hairy), yellow. Pistillate flowers up to 7.5 mm diam.; pedicel 3.3 – 5 mm long; pistil: (gynophore up to 0.4 mm high), ovary ovoid, 1–1.3 mm high, styles 3, 0.3 –1.2 mm long, stigma lobes 1– 2 mm long. Fruits 8 –18 by 80 –18 mm, yellow turning reddish brown, glochidiate hairs c. 3 mm long. Seeds 5.2 – 5.5 by 3.5 – 5 by 2.7– 3.5 mm; aril red. Embryo ovoid, flattened, c. 4.3 by 3 mm; plumule and radicle c. 0.7 mm long. — Fig. 1; Plate 1; Map 1.

 

 

Habitat & Ecology — Often common, but scattered in (hilly) primary and second- ary lowland forest, mixed dipterocarp forest, coastal peat-swamp forest (kerangas), seasonally swampy forest, Schima-bamboo forest, along beaches and river banks, and in submontane scrubs. Soil: yellow, brown or black sandy soil, sandy loam, sandstone, yellow clay, clay-loam, rocky coral, or granite. Altitude: sea level up to 500 m. (Partly after Airy Shaw 1972, 1975, 1981.) According to Whitmore (1973) a calcifuge, because it is common along the coast in NE Malaysia and the inland collections may reflect old Pleistocene shore lines. However, the plants are also found in a far more acid surround- ing, therefore, Ch. castanocarpa is more likely to be a very tolerant species capable of growing in a wide variety of soils. Flowering and fruiting throughout the year.

Uses — In NE Malaysia (Kelantan and Trengganu) the young leaves are cooked and eaten as spinach or chopped up with rice (Corner 1940). The wood is used as a non-construction timber by the Iban, Sarawak, Borneo (Jarvie & Perumal 1994), for building purposes in Ceylon (Gamble 1902), and for sampans and columns in Indochina (Gagnepain 1926). The wood is said to be light red, moderately hard, close-grained, pores small, scanty, in short radial lines, medullary rays very fine, very numerous, nar- row wavy concentric bands fairly regular and prominent (Gamble 1902, Welzen 1998).

Malesian vernacular names — Malaysia: Batu, Membatu (Corner 1940). Sumatra: Besie, Kaju besi(e) (Malay). Borneo: Dengin-bobok (Bassap-Mapulu); Dusun bukit (Tidong); Kaju dusun, Nampadu (Malay); Masam (Serawak-Dyak); Mauhi (Bajar Ma- lay); Medang serukan (Brunei Dusun); Pingas (Sungei); Rr'teh r'teh (Medong Serokan); Boekir, Djamilas, Djentian, Oebar bantan, Perupuk batu (Kalimantan area); Obah nasih (Sandakan Prov.).

Notes — 1. Kuntze (1891) made a new combination in the genus Gaedawakka L. (Fl. Zeyl. 1747: 203). This combination is superfluous, because the description of Gaedawakka predates the starting date of 1 May 1753 (art. 13.1a, I.C.B.N. 1988).

2. One specimen with pistillate flowers (Forest Guard 3, Malaysia, BM) showed 3 filaments attached to the gynophore, all other pistillate flowers were devoid of stamens.

3. The species is fairly constant, the infraspecific variation is quite narrow. Leaves on the Malay Peninsula are usually much larger than those on Sumatra, with the Bornean specimens in between. The pilosity varies, plants in Malaysia are (early) glabrous, while on Sumatra and especially in NE Borneo the leaves can be subpilose and the branches pilose, although glabrescent. On Borneo the leaves tend to be more elliptic than ovate (Malaysia, Sumatra). The staminate flowers in the Malay Peninsula are usually much larger than those on Sumatra, also with the Bornean specimens in between.