Horsfieldia
Content
Description
Tree 10-35 m.
Leaves membranous, elliptic-oblong to oblong(-lanceolate), 12-26(-30) by 4—9(—11) cm, base cuneate, apex acute-acuminate;
Inflorescences with sparse to dense dendroid hairs 0.2-0.5 mm, sometimes glabrescent;
Fruits 4-12(-20) per infructescence, broadly ellipsoid, apex narrowly rounded, base (broadly) rounded, 2-2.8(-3) by 1.8-2.2(-2.6) cm (see note 3), glabrous, drying brown to dark brown, neither warted nor lenticellate, pericarp 1.5-4 mm thick;
Distribution
Asia-Tropical: Borneo present (Brunei present, Sabah present, Sarawak present); Malaya (Peninsular Malaysia present, Singapore absent); Sumatera (Sumatera present), C, E & NE Kalimantan present, Johore present, Kedah present, Kelantan present, Malacca present, Pahang present, Peninsular Thailand present, Perak present, Trengganu present, large parts of Kalimantan absent
Peninsular Thailand; Malesia: Sumatra, Peninsular Malaysia (Kedah, Kelantan, Perak, Trengganu, Pahang, Malacca, Johore), Borneo (Sarawak, including one deviating collection, see note 3; Sabah; C, E & NE Kalimantan; Brunei); not found in Singapore and large parts of Kalimantan
Taxonomy
1 Horsfieldia brachiata is close to H. polyspherula, and in most cases easily recognized by its weak to strong raised lines on the twigs. Its fruits are rather uniform in shape and size, 20-28 mm long, and thus ± intermediate between those of H. polyspherula var. polyspherula and var. sumatrana (see there). The leaves of H. brachiata are rather like those of H. polyspherula var. sumatrana, namely generally membranous and drying pale, dull olivaceous above and pale cinnamon below. Its flowers are rather uniform, with mature male buds 1.2-1.8 mm in diameter, and the androecium usually ± triquetrous with 6-10 stamens (but see note 2), and they do not differ from those of H. polyspherula s.l. Sterile and flowering collections in which the apical and lower twig parts are not sufficiently represented may be difficult to place. Horsfieldia brachiata generally has stouter inflorescences than H. polyspherula and is quite common in evergreen forests in Peninsular Thailand; H. polyspherula has not been found there.
2 The species usually has 12-16 thecae in the androecium, but material from Peninsular Thailand may have 18 or 20 thecae.
3 S 34908 from Sarawak (Kapit, 5th Div.) is a stout specimen, in bad condition, with female flowers; at L there is a single fruit measuring 40 by 30 mm, with the pericarp ± woody, 5-7 mm thick. Horsfieldia brachiata is not common in Sarawak and this large- fruited specimen probably represents a separate taxon. It was collected in a kerangasmossy forest at c. 800 m altitude, higher than any other specimen of the species.