Dimorphocalyx denticulatus Merr.

2. Dimorphocalyx denticulatus Merr. View in CoL — Fig. 1b, d, e View Fig ; Map 2

Dimorphocalyx denticulatus Merr. (1909) 278; Pax & K.Hoffm. (1912) 285; Merr.(1923) 455; Airy Shaw (1975) 96; (1983) 20. — Type: FB ( Whitford & Hutchinson) 9033 (holo PNH†; iso K, US), Philippines, Mindanao, District of Zamboanga, Port Banga .

Dimorphocalyx murinus Elmer (1911) View in CoL 1285 (‘ murina ’); Pax & K.Hoffm. (1914) 404; Merr. (1923) 455; Whitmore (1973) 87; Airy Shaw (1975) 97; (1983) 21. — Lectotype (designated here): Elmer 12844 (holo L; iso BM, HBG, K, L, NY, P, U under D. lawianus, US View in CoL ), Philippines, Palawan, Puerto Princesa (Mt Pulgar).

Dimorphocalyx loheri Merr. (1925a) View in CoL 30; (1925b) 252;Airy Shaw (1920) 413; (1983) 20. — Lectotype (designated here): Loher 12467 (holo UC; iso A), Philippines, Luzon , Rizal Prov., Montalban.

(Under)shrubs to trees, to 20 m high, dbh to 20 cm; flowering branches 1–2.5 mm thick, round, slightly striate, often strongly lenticellate, hairy when young, persistent at nodes. Indumentum of light yellow hairs, present on most parts. Outer bark green to pale white to greyish to grey-brown to light brown, smooth to deeply fissured to scaly, thin to 4 mm thick, soft (to hard); inner bark 0.3‒0.5 cm, pale yellowish to pink to red to red-brown to (pale) brown, fibrous, (soft to) hard; exudate red; sapwood creamy white and dull ochre, c. 2 cm thick; heartwood light red-brown. Stipules ovate, 3‒5 by 2.2‒3.8 mm, outside (glabrous to) hairy, glabrescent, inside glabrous. Leaves: petiole 2‒10 mm long (see note 2), 1–3.1 mm diam, completely pulvinate, usually slightly hairy; blade elliptic, widest in ± middle, 7.9–30 by 3.3–12 cm, 1.8–3.2 times as long as wide, rather coriaceous, base rounded to cuneate, margin serrulate to serrate, revolute, apex (acuminate to) cuspidate to caudate, upper surface seldom with few hairs, dull dark green, lower surface often with few hairs, light green to glaucous, venation slightly raised to slightly sunken above, raised below, secondary veins 8–17 pairs, intercalary veins present, tertiary nerves and veinlets reticulate. Inflorescences axillary, cymose to thyrsoid, usually short, to 5 cm long, round to flattened and angular, (sparsely) hairy; staminate flowers in groups per node, pistillate flowers single per node and often single per inflorescence; bracts in various shapes, very broad and short to long, narrow and sharply folded to leaf-like, triangular to ovate to elliptic, 1.8–8 by 1.3–4 mm, margins thinner, with lighter colour when dry, outside (very) hairy, inside glabrous. Staminate flowers 10–13 mm diam, white; pedicel to 10 mm long above basal abscission zone, round, (slightly) hairy; calyx lobes often unequal, 4.3–5 mm deep, lobes ovate, 2.4–3 by 1.9–2.6, apex slightly emarginate to rounded, outside (glabrous to) hairy, inside glabrous (to basally slightly hairy); petals oblong to obovate, 5.3–7.3 by 2.6–3.6 mm, usually outside slightly hairy, apex rounded; disc glands rather thick, zig-zagging around stamens, hairy; stamens 16–18, the outer ones with (nearly) free filaments of c. 2 mm long, the inner ones diverging in two layers from an up to 2 mm long androphore, free part of filaments c. 1.5 mm long, anthers c. 0.7 by 0.7 mm. Pistillate flowers 12–22 mm diam; pedicel c. 9 mm long, round, hairy; sepals connate at base, lobes enlarging directly after opening (see note 3), obovate, c. 8.2 by 4.2 mm, green, outside hairy, inside glabrous, apex rounded; petals elliptic to oblong, 4.8–9 by 3–6 mm, usually shorter than calyx lobes, white, hairy outside, glabrous inside, apex rounded; disc a flat ring, hairy, cream; ovary 2.5–4 by 2–4 mm, hairy (to perhaps seldom glabrous), glabrescent, green, stigmas 3–7 mm long of which upper 0.9–5 mm split, thick, broad, hairy below, green to yellow. Fruits 1.3–1.7 by 1–1.3 cm, smooth, hairy, glabrescent, green to slightly brownish green to greenish blue to purple, also cream mentioned; wall woody, 1–1.2 mm thick, exocarp often separating; pedicel elongating up to 25 mm; sepals enlarged to 12.8 by 5 mm (see note 3); columella 7–12 mm long. Seeds 8–12 by 6.5–10.5 by 5.5–9 mm.

Distribution — Malay Peninsula (Johore), W and Central Borneo, Philippines.

Habitat & Ecology — Mixed dipterocarp lowland forest to logged over areas on hillsides, ridges and along rivers; soil blackish sand to sandy clay to loam to sandstone shale; bedrock igneous intrusive. Altitude: sea level to 700 m. Flowering: March to November; fruiting: February, March, May to August, October to December.

Vernacular names — Borneo:Kalimantan Barat:Buronte girek; Sabah: Alag alag, putat putat (Tidong); Binsuon, Parumpong (Dusun Kinabatangan). Philippines: Dagongdong, Pagangdong (Tagbanua).

Notes — 1. The type of D. denticulatus resembles the specimens of D. pauciflorus of Borneo. However, D. pauciflorus has echinate fruits, and the presence of spines on the ovary of D. denticulatus was not described by Merrill (1909). In habit the type of D. denticulatus resembles other Philippines specimens identified as D. murinus Elmer (serrulate leaf margin, short petioles). Therefore, the latter, younger name is synonymised with D. denticulatus .

2. Dimorphocalyx loheri is tentatively placed in the synonymy here. Airy Shaw (1983) suggested “Genus uncertain, probably not Dimorphocalyx , but available material insufficient”. However, according to the description by Merrill (1925; “unfortunately flowering isotypes are absent and the holotype is lost”) this species is more like D. murinus , because of the hairy floral parts, than D. denticulatus ; names which are here considered as conspecific.

3. SFN (Corner) 37248 from Johore, Malay Peninsula, has pistillate sepals that do not directly enlarge when the flower opens, similar to a specimen with unknown collector and origin (L, barcode L0158646). The latter also has exceptionally long petioles (up to 16 mm long), but still has the typical D. murinus hairy disc.