Volume 16 > Part 1 > Year 2022 > Page 205 > Annonaceae > Monoon

5. Monoon fuscum (King) B.Xue & R.M.K.Saunderswfo-0001334292

Taxon 61: 1031. 2012.— Griffithia fusca King, Ann. Roy. Bot. Gard., Calcutta 4: 10, t. 220. 1893.— Griffithianthus fuscus (King) Merr., Philipp. J. Sci., C 10: 231. 1915.— Enicosanthum fuscum (King) Airy Shaw, Bull. Misc. Inform. Kew 1939: 277. 1939. Plate XXIV: E–F.

Accepted Name : This is currently accepted.

Description : Tree up to 18 m tall, bark slightly rough, greyish brown to dark brown. Twigs golden brown-tomentose, with conspicuous lenticels. Leaves thinly coriaceous, asymmetrically oblanceolate or obovate, 12‒18(–20) by 3.5‒6.5 cm, base rounded, asymmetrically rounded, truncate, cuneate, or subcordate, apex acute to acuminate, the acumen 4‒8 mm long, glabrous on both surfaces except for pubescence along veins, midrib shallowly grooved above, secondary veins fairly straight, 12‒16(‒18) per side, tertiary venation percurrent; petioles 5‒8 mm long, flat above, golden brown-tomentose. Inflorescences axillary on leafy twigs, 1-flowered, peduncle 2–4 mm long, pedicels 4‒7 mm long, 2–2.5 mm thick, golden brown-tomentose, each bearing 2 ovate bracts, 3‒4 by 4–5 mm at the base; buds subglobose. Sepals imbricate, free, coriaceous, ovate, 4‒6(‒7) by 5‒7(‒8) mm, apex acute, golden brown-tomentose outside. Petals valvate from near the base to the apices, greenish or greyish white to pale yellow, coriaceous, oblong, curved outward from midpoint to apex, surface verrucose outside, apex acute, longitudinal veins slightly conspicuous, golden brown-tomentose on both sides; outer petals 25‒40 by 10‒12 mm; inner petals 20‒35 by 8‒10 mm, base incurved over the stamens. Stamens cuneate, 2.5–3 mm long, anther connective apex truncate. Carpels up to 5 per flower, 2.7–3 mm long, stigmas level with anther connective apices, capitate, 0.4–0.6 mm in diam., tomentose. Receptacle conical, 3.5–4.5 mm in diam., 3.5–4 mm thick, pubescent. Fruits of up to 5 monocarps borne on a pedicel 6‒12 mm long, 2.2–2.4 mm thick. Monocarps green to dark green when mature, ovoid, 2.2‒2.5 by 1‒1.2 cm, tomentose, apex with a beak 5–7 mm long, base rounded, stipe 3‒5 mm long, 1.5‒2 mm thick; pericarp ca 1 mm thick. Seed subglobose, 16‒18 by 8‒10 mm, brown to red-brown, smooth, often shiny.

Thailand : SOUTH-WESTERN: Prachuap Khiri Khan; PENINSULAR: Ranong, Nakhon Si Thammarat, Phatthalung, Songkhla, Yala.

Distribution : Peninsular Malaysia (type).

Ecology : Dry evergreen forests, 50‒800 m alt. Flowering: January–April; fruiting: February‒May.

Vernacular : Sang yu (ซังหยู)(Nakhon Si Thammarat); nang na phon ting (หนังหนาผลติ่ง).

Notes: The verrucose petals and monocarp surface, and the monocarp apex with a distinct beak are distinctive characters of the species. The species differs from Monoon cupulare and M. ornithocephalum as indicated in the key. Spherical galls are often present on the leaves. The specimen Puudjaa 1202 -BKF from Narathiwat Province is similar, but has petals 40‒52 mm long and a leaf acumen 10‒20 mm long.