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Ultimate Kratom Resource

The Philippine Rubiaceae Genera

Mitragyna Korth by G. Alejandro and S. Liede


Nauclea auct. non L.,Stephegyne Korth., Mamboga Blanco, Paradina Pierre ex Pitard, Hallea Leroy.

Type species:

Lectotype, Mitragyna parvifolia (Roxb.) Korth.

Classification: Subfamily:

Cinchonoideae; Tribe: Coptosapeltae.

Habit and vegetative parts:

Trees, 2–8 m high, without succulent tuber. Spines absent. Raphides absent. Vegetative parts not foetid when bruised. Stem glabrous or puberulous, branched. Branches and branchlets glabrous, or pubescent. Adventitious roots on internodes absent. Stipules interpetiolar, not fused, entire or bifid (rarely, somewhat foliaceous those subtending the flowers), large, ovate to ellipitic, glabrous, margin not hairy, colleters present (at the base inside), caducous. Leaves opposite, isophyllous. Lamina membranous to papery or semi-leathery, 6–8(–14) cm long, 3–4(–9) cm wide, ovate to elliptic; apex acuminate (short); base sub cordate, not decurrent; not ciliated on the margins; upper surface glabrous; lower surface glabrous or pubescent, sparse; petiolate; lateral nerves prominent, 5–10(–15) pairs. Petiole 1–2.5 cm long, pubescent, sparse, not winged. Domatia present (in axils of the lateral nerves), or absent.

Reproductive parts:

Inflorescences present, terminal, flowering heads solitary or fascicled, pseudanthial, on an unbranched axis or on a branched axis, inflorescenses pattern thyrses or dichasial; involucral bracts present; interfloral bracts and bracteoles present. Flowers 5 merous, actinomorphic, bisexual, homostylous, without semaphylls, fragrant; pedicel absent or present, pubescent. Calyx tube extremely reduced (<2 mm long) or cup-shaped to shortly tubular (>2 mm long), hairs present or absent; lobes reduced to minute teeth or low ridge (<2 mm), lobes equal, lobes glabrous or pubescent; colleters absent. Corolla infundibular to salverform (narrow), less than 1 cm long; tube glabrous outside, inner part glabrous to pubescent (dense); lobes elliptic; aestivation valvate; abaxial side glabrous; adaxial side glabrous; margin not hairy. Stamens inserted distal 1/4 of corolla tube, separate, of equal sizes. Filaments distinct (>1mm), not hairy. Anthers basifixed, exserted in corolla tube or semi-exserted in corolla tube, linear, dehiscing via longitudinally slits. Style exserted in corolla tube, filiform, hairs absent. Stigmas entire, clavate, papillate. Ovary bilocular; placentation axile. Ovule 2 per locule, not pendulous. Fruits non-fleshy, not multiple, splitting, loculicidal and septicidal, capsular, subglobose or ellipsoid; ridges or grooves absent; crown of calyx segments present, or absent. Seeds numerous, not angular, winged, endospermic; exotestal cells isodiametric, with thickenings, in the inner tangential walls and along the radial wall; isolated fibers absent.

Pollen binucleate; aperture 3; colporate.

Distribution– Continental Africa, in Asia and Malesia.

Number of Species- 7.

Philippine species- M. speciosa (Korth) Havil, M. diversifolia (Wall. Ex G.Don) Havil (Mitragyna rotundifolia (Roxb.) O.Kuntze).

Useful literature- Ridsdale, C.E. 1978. A revision of Mitragyna & Uncaria. Blumea 24: 43–100.