Memecylon interjectum R. D. Stone 2006, sp. nov.
Creators: name: Stone, Robert Douglas
Publisher: name: Zenodo
Year: 2006
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Myrtales
Melastomataceae
Memecylon
Memecylon interjectum

description: <i>Memecylon interjectum</i> R.D.Stone, sp. nov. (Fig. 7) <i>Similis</i> M. perangusto Jacq.-Fél. <i>sed laminis latioribus, inflorescentiis plerumque ad nodos inferiores defoliatos non in axillis foliorum, bracteis brevibus squamiformibusque non acicularibus, pedicellis longioribus differt.</i> TYPUS. — <b>Madagascar.</b> Antsiranana province, Masoala peninsula, canyon of the upper Ampanavoana river, 15°37’40”S, 50°04’30”E, alt. <i>c.</i> 250 m, shallow soil of steep, east-facing rock outcrop on west side of river, 10.XII.2001, <i>Stone et al. 2408</i> (holo-, CAS; iso-, CAS, G, K, MO, P, TAN, TEF, UC, US, WAG; fruits in spirit collection at CAS). DESCRIPTION Shrub 2 m high; branchlets narrowly 4-winged when young (the wings often slightly crisped), becoming terete with age; internodes 1.5-3.5 cm long; axils with a small tuft of persistent bristles 1.5-2 mm long. Leaves thin but firm (neither coriaceous nor papyriferous), bright green on the upper surface (when dry), somewhat paler below, both surfaces dull and finely granular-rugose; petioles 1.5-2.5 mm long; blades broadly lanceolate, 5-8 cm long, 1.5- 2.4 cm wide, cuneate at base, attenuate and acute or ± acuminate at apex; mid-nerve impressed on the upper surface, prominent and yellow-coloured on the lower; transverse veins scarcely visible, oriented at an oblique angle relative to the mid-nerve. Cymes 1.5 cm long, mostly 5-flowered, umbelliform or with a short axis above the peduncle, solitary or fascicled in the lower axils and also at the nodes below the current leaves; peduncles (1-)2-3(-4) mm long; bracts squamiform, deciduous; pedicels slender, 4- 6 mm long. Flowers not seen. Fruits globose, 5 mm in diameter; calycinal crown erect, 4-microdentate; epigynous chamber with partitions cruciform, scarcely pronounced. REMARKS This species is known only from the type collection. It has the acute leaf apices of <i>M. perangustum</i> but differs conspicuously from that species by its wider leaves (which in <i>M. perangustum</i> are mostly 0.9-1.5 cm wide, rarely to 1.9 cm). Another seemingly close relative, <i>M. gracilipedicellatum</i> Jacq. -Fél., differs from both of the aforementioned species in having leaf blades less than three times longer than wide with apices obtuse. Here it must be mentioned that <i>M. perangustum</i> is somewhat variable in its leaf morphology. The type (<i>Rakotoniaina RN-2365</i>, P) has narrowly lanceolate leaves that are abruptly rounded and then narrowly cordate at the base, as does one other collection (<i>Rakotoniaina RN-5928</i>, P). In four other specimens from the type region, the leaf bases are gradually narrowed to the petiole and not at all rounded or cordate (<i>Rakotoniaina RN-2431</i>, <i>Rakotoniaina RN-2634</i>, <i>Rakoto Jean de la Croix RN-7718</i>, and <i>Razanaparany RN-8748</i>; all at P). A recent collection from the Réserve naturelle intégrale de Betampona (<i>Andrianarisata 151</i>, CAS, MO, P) has leaves less than six times longer than wide; these specimens do not key cleanly to <i>M. perangustum</i> in Jacques-Félix (1985a) and superficially resemble <i>M. interjectum</i>, but their acicular inflorescence bracts and short pedicels nonetheless identify them as <i>M. perangustum</i>.
description: Published as part of <i>Stone, Robert Douglas, 2006, New species of Memecylon L. and Warneckea Gilg (Melastomataceae) from Madagascar and Mayotte, pp. 337-358 in Adansonia (3) (3) 28 (2)</i> on pages 348-350, DOI: 10.5281/zenodo.5187074