Volume 15 > Part 1 > Year 2021 > Page 88 > Rubiaceae > Mitragyna

1. Mitragyna diversifolia (Wall. ex G.Don) Havil.wfo-0000244928

J. Linn. Soc., Bot. 33: 71. 1897; Ridsdale, Blumea 24: 65. 1978; Tao Chen & C.M.Taylor in Z.Y.Wu et al., Fl. China 19: 219. 2011.— Nauclea diversifolia Wall. ex G.Don, Gen. Hist. 3: 467. 1834.— N. parvifolia var. diversifolia (Wall. ex G.Don) Kurz, Forest Fl. Burma 2: 67. 1877.— Stephegyne diversifolia (Wall. ex G.Don) Hook.f., Fl. Brit. India 3: 26. 1880, p.p. Plate VII: C.

Accepted Name : This is currently accepted.

Synonyms & Citations :

Description : * ‘var. microphylla’ has been wrongly applied to small-leaved plants of Mitragyna diversifoliafrom Thailand. The variety is associated with M. parvifolia (Roxb.) Korth. [var. microphylla (Kurz) Ridsdale; syn. Nauclea parvifolia Roxb. var. microphylla Kurz], a taxon not recorded from Thailand but from India and Sri Lanka.

Deciduous small trees to ca 8 m, rarely taller; bark grey to dark grey-brown; terminal vegetative bud obovate to oblong in outline, flattened. Stipules obovate to oblong, 1–1.5 by 0.5–1 cm, often slightly keeled, pubescent outside. Leaves oblong, obovate or orbicular, (4–)6–14(–16) by (2.5–)3–9(–12) cm, base rounded to obtuse, rarely ± cuneate, apex rounded or obtuse, chartaceous to subcoriaceous, glabrous above, pubescent along veins beneath, lateral veins 5–10 pairs, quite ‘steep’ veins (angle between midrib and veins 10–30°), hairy domatia present in vein axils; petiole 1–2.5 cm long, pubescent. Inflorescences terminal on often repeatedly branched side shoots of main lateral branches, consisting of (3–)5–9(–15) flowering heads in thyrse- to pseudo-umbel-like. Flowering heads 0.6–1 cm in diam. across calyces, 1.5–2 cm across corollas; interfloral bracteoles linear-spathulate, 2–3 mm long, usually glabrous, exceptionally ciliate, reaching about same length as varies (hence calyx lobes clearly visible in young heads). Calyx ca 1.5 mm high, glabrous, tubular below; lobes obtuse to rounded or broadly triangular, entire. Corolla creamy white to (pale) yellow, often turning darker with age; tube hypocrateriform to narrowly infundibular, 3–4 mm long, outside glabrous, inside densely hairy, hairs protruding from throat; lobes narrowly elliptic, 2.5–3.5 mm long, inside hairy at base, outside glabrous. Stamens with filaments to 1 mm long; anthers 1.5–2 mm long, exserted from throat, spreading. Ovary ca 1.5 mm high, glabrous; style plus stigma exserted for 6–7 mm; stigma 1.5–2 mm long. Fruiting heads 1.3–1.8 cm in diam. Fruitlets ca 5 mm long, glabrous, crowned by persistent calyx.

Thailand : NORTHERN: Chiang Mai, Chiang Rai Lamphun, Phitsanulok, Kamphaeng Phet, Nakhon Sawan; NORTH-EASTERN: Loei; EASTERN: Chaiyaphum; SOUTH-WESTERN: Ratchaburi; CENTRAL: Chai Nat, Saraburi, Pathum Thani, Krung Thep Maha Nakhon (Bangkok); SOUTH-EASTERN: Prachin Buri; PENINSULAR: Surat Thani, Nakhon Si Thammarat, Satun.

Distribution : Bangladesh, China (Yunnan), Myanmar (type), Indochina, Peninsular Malaysia, Java, the Philippines.

Ecology : Dry dipterocarp forests, dry deciduous forests, often in disturbed sites such as old rice fields, frequently left as shade tree at the edge of rice fields, 0–400 m alt. Flowering: July–August; fruiting: November–February.

Vernacular : Kra thum na (กระทุ่มนา), kra thum nam (กระทุ่มน้ำ)(Central); kra thum dong (กระทุ่มดง)(Kanchanaburi); kra thum khi mu (กระทุ่มขี้หมู), tum nam (ตุ้มน้ำ), tum noi(ตุ้มน้อย), tum sae (ตุ้มแซะ)(Northern); thom khi mu (ท่อมขี้หมู)(Songkhla); thom na (ท่อมนา)(Surat Thani); thom noi (โทมน้อย)(Phetchabun); thom pai (ถ่มพาย)(Loei); ka-tum (กาตูม)(Kmer-Prachin Buri); tam (ตำ)(Suai-Surin).