Guatteria simiarum Buchanan-Hamilton ex J. D. Hooker & Thomson, Fl. Ind. 1: 142. 1855; Polyalthia cheliensis Hu; P. simiarum subsp. cheliensis (Hu) Bân; Unona simiarum (A. Hamilton ex J. D. Hooker & Thomson) Baillon ex Pierre.

Trees to 25 m tall. Bark grayish white. Branches puberulent when young, glabrous and sparsely lenticellate with age. Petiole 5-10 mm, robust; leaf blade ovate-oblong, oblong, lanceolate, or oblanceolate, 9-28 × 3.5-12.5 cm, membranous to papery, hyalopunctate, glabrous or puberulent only on midvein, secondary veins 13-20 on each side of midvein, oblique, close-set, parallel, and prominent on both surfaces, base rounded to broadly cuneate and sometimes oblique, apex acuminate, shortly acuminate, or obtuse. Inflorescences axillary or on older or short branches, 1- to several flowered; bracts ovate, tomentulose. Pedicel ochraceous, 2.5-4 cm, tomentulose, bracteolate near base to middle. Sepals ovate-triangular, ca. 5 × 5 mm, outside pubescent, inside glabrous. Petals yellowish green; outer petals ± longer than inner petals; inner petals linear-lanceolate to linear, 1.5-3.5 × 0.3-0.4 cm, outside puberulent, inside ± glabrous. Stamens oblong; connectives apically broadly truncate to convex. Carpels oblong, pubescent; ovule 1 per carpel, basal; stigmas capitate, puberulent. Fruiting pedicel 2-3 cm; monocarp stipes 3-3.5 cm, glabrous; monocarps ovoid to ovoid-ellipsoid, 2.5-3 × 1.2-1.7 cm, glabrous. Seed 1 per monocarp. Fl. Apr-Sep, fr. Jul-Dec. 2n = 14.

The record of Goniothalamus macrophyllus (Blume) J. D. Hooker & Thomson from the Flora area (X. L. Hou, http://www.abclunwen. com/lunwen-free-387606/; accessed on 25 Nov 2010) was based on a misidentification of Polyalthia simiarum.

Forested slopes; 500-1200 m. S and SW Yunnan [Bhutan, Cambodia, India, Laos, Myanmar, C and N Thailand, Vietnam].