e-Flora of Thailand
Volume 16 > Part 1 > Year 2022 > Page 206 > Annonaceae > Monoon
7. Monoon hookerianum (King) B.Xue & R.M.K.Saunderswfo-0001334296
Taxon 61: 1032. 2012.— Polyalthia hookeriana King, J. Asiat. Soc. Bengal, Pt. 2, Nat. Hist. 61: 57. 1892.
Accepted Name : This is currently accepted.
Synonyms & Citations :
Description : Tree up to 25 m tall, bark smooth, dark brown-grey. Twigs dark grey, pubescent with conspicuous lenticels. Leaves chartaceous, asymmetrically oblanceolate to obovate, 11‒18 by 4‒7 cm, base asymmetrically cuneate or obtuse, apex cuspidate to acuminate, the acumen 5‒15 mm long, glabrous on both surfaces except for pubescence along midrib, midrib grooved above, secondary veins fairly straight, 10‒12 per side, tertiary venation percurrent; petioles 5‒7 mm long, flat above. Inflorescences in supra-axillary fascicles on leafy or leafless twigs, 2‒7-flowered, peduncle 4‒6 mm long, rachis 6‒10 mm long, pedicels 25‒40 mm long, 2.2‒2.5 mm thick, pubescent, each bearing an adnate ovate bract 4–5 by 3–4 mm between the base and the midpoint; buds ovoid. Sepals valvate, thinly coriaceous, ovate, 5‒7 by 4‒5 mm, apex sub-acute and slightly spreading, pubescent outside and glabrous inside. Petals imbricate at the apices, moderately spreading, pale yellow, thinly coriaceous, base slightly incurved, apex acute or sub-acute, puberulous outside and glabrous inside; outer petals oblong, 25‒35 by 8‒10 mm; inner petals oblanceolate, 35‒40 by 12‒15 mm. Stamens cuneate, 1‒1.2 mm long, anther connective apex truncate. Carpels numerous, 1.8‒2 mm long, ovaries ca 0.5 mm long, stigmas higher than anther connective apices, clavate, 0.6‒0.8 mm long, pubescent. Receptacle cushion-shaped, 4‒5 mm in diam., 1.5‒2 mm thick, pubescent. Fruits of up to 20 monocarps borne on a pedicel 25‒35 mm long, 5‒7 mm thick. Monocarps greenish yellow to red when mature, elliptic to sub-oblongoid, 1.8‒2.2 by 1.5‒1.8 cm, glabrous, apex blunt to sub-acute, base obtuse, stipe 35‒40 mm long, 1.8‒2 mm thick, glabrous; pericarp ca 1 mm thick. Seeds unknown.
Thailand : PENINSULAR: Narathiwat.
Distribution : Peninsular Malaysia (type), Singapore, Borneo.
Ecology : Tropical rain forests, ca 380 m alt. Flowering and fruiting: June.
Vernacular : Kui so (กุยโซ)(Yawi-Narathiwat).
Notes: The specimen Kerr 12361 -BK from Surat Thani Province is similar to Monoon hookerianum in its pedunculate inflorescence but has leaves with 16‒20 secondary veins per side.