Volume 16 > Part 1 > Year 2022 > Page 215 > Annonaceae > Monoon

16. Monoon phukraduengense Bunchaleewfo-1000040839

Thai Forest Bull., Bot. 50(1): 12. 2022.

Accepted Name : This is currently accepted.

Synonyms & Citations :

Description : Tree up to 25 m tall, bark brown, smooth. Twigs puberulous with conspicuous lenticels. Leaves thinly coriaceous, asymmetrically elliptic to oblanceolate, 11‒18 by 3.5‒7.5 cm, base cuneate to broadly cuneate, apex acuminate, the acumen 5‒12 mm long, glabrous on both surfaces, midrib grooved above, puberulous, eventually glabrous, secondary veins fairly straight, 16‒18 per side, tertiary venation percurrent; petioles 5‒7 mm long, shallowly grooved above, glabrous. Inflorescences forming fascicles in axils of leafy twigs or on tubercles of leafless twigs, 1‒4-flowered, pedicels 25‒30 mm long, 1.2‒2 mm thick, glabrous, each bearing one adnate ovate bract 1.5‒1.7 by 1.2‒1.4 mm at the base, pubescent outside; buds broadly ovoid. Sepals valvate, free, chartaceous, ovate, 2.5‒3 by 3‒4 mm, apex acute, sparsely hairy outside and glabrous inside. Petals imbricate at the apices, erect, green to yellowish green, purplish red on inner base, thinly coriaceous, oblong, apex acute, glabrous on both sides; outer petals 35‒40 by 7‒9 mm; inner petals 30‒35 by 5‒6 mm. Stamens numerous, slightly cuneate to oblong, 0.8‒1 mm long, anther connective apex truncate. Carpels numerous, 1‒1.2 mm long, pubescent, stigmas higher than the anther connective apices, oblong, ca 0.4 mm long, pubescent. Receptacle cushion-shaped with a slightly concave apex, 5–6 mm in diam., 2.5‒3 mm thick, pubescent. Fruit of up to 30 monocarps borne on a pedicel ca 40 mm long, 1.5‒2 mm thick. Monocarps yellow, dull greenish red, or dark red, oblongoid, 3‒3.5 by 2‒2.5 cm, smooth, glabrous, apex and base obtuse, stipe ca 40 mm long, 10‒12 mm thick. Seeds unknown.

Thailand : NORTH-EASTERN: Loei (Phu Kradueng, Phu Suan Sai NP – type: Suddee et al. 4479, holotype -BKF).

Distribution : Endemic.

Ecology : Hill evergreen forests or semi-evergreen forests, 700–1,222 m alt. Flowering: January‒June; fruiting: January, March, May‒September.

Vernacular : Saban nga phu kradueng (สะบันงาภูกระดึง).

Notes: Monoon phukradungense was described and illustrated by Chalermglin (2001, p. 314‒315) as Polyalthia sp. Its greatest similarities are to M. laui, a species of Hainan and Vietnam, and M. phuluangense. All three species are notable for the large number of carpels.