Memecylon perditum 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 perditum

description: <i>Memecylon perditum</i> R.D.Stone, sp. nov. (Fig. 5) <i>A speciebus ceteris</i> Memecyli madagascariensis <i>combinatione foliorum obovatorum, cymularum breviter pedunculatarum ad axillas foliorum vel nodos aphyllos defoliatosve, florum usque 3 subsessiliumque ad par bractearum cucullatarum subtentorum cum floribus centralibus itidem bibracteolatis, connectivo antherarum dorsaliter glanduloso, fructuum globosorum 6 mm diametro distinguenda.</i> TYPUS. — <b>Madagascar.</b> Antsiranana province, Masoala peninsula, valley of Iketra river, affluent to the Anaovandrano, along foot path between Iketra and Antanambao Rantavato (valley of Ampanavoana river), 15°43’05”S, 50°13’05”E, alt. <i>c.</i> 50 m, understory of evergreen rain forest, 6.XII.2001, <i>Stone et al. 2402</i> (holo-, CAS; iso-, CAS, K, MO, P, TAN). PARATYPES. — <b>Madagascar.</b> Antsiranana province, Besamatrakely forest, Ambanja, XII.1963, <i>Rakotozafy 341</i> (P). — Antsiranana province, Réserve naturelle intégrale de Marojejy, near summit of Ambatosoratra, 14°32’S, 49°42’E, alt. 1583 m, VI.1994, <i>Ravelonarivo et al. 229</i> (CAS, P). DESCRIPTION Evergreen shrub or tree 5-30m high; branchlets terete and becoming ± thickened at the nodes; successive nodes alternately bearing normal leaves and floral bud scales (modified leaves); internodes 1-2.5 cm long.Leaves with petioles 3-7 mm long; blades thinly coriaceous, granular-rugose on both surfaces (when dry), obovate, 3.5-6 cm long, 1.7-3.3 cm wide, attenuate at base then decurrent with the petiole, rounded and obtuse or even slightly retuse at apex; only the mid-nerve clearly visible, canaliculate on the upper surface, ± prominent on the lower toward the base; transverse veins obscure or faintly visible on the lower surface, oblique relative to the mid-nerve. Cymes contracted, less than 1 cm long, 1-3-flowered, borne either in the leaf axils, at the intervening (scale-bearing) nodes, or at the defoliated nodes of older branchlets; peduncles 1-2.5 mm long, axes absent or very short; bracts persistent, lanceolate, <i>c.</i> 1 mm long, acute to apiculate at apex, cucullate, connate at base; bracteoles subtending only the central flower, approximately the same length and shape as the bracts. Flowers subsessile (pedicels up to 0.5 mm long); hypantho-calyx white, cupuliform to slightly urceolate or obconic, <i>c.</i> 3 mm long and 2-3 mm wide; calyx 4-lobed in bud, the margin becoming broadly sinuate and 4-microdentate at anthesis. Corolla acute to shortly acuminate in bud; petals violet, lanceolate-acuminate, 3.5 mm long, <i>c.</i> 1 mm wide, the base distinctly auriculate then short-unguiculate (claw to 0.5 mm long). Anthers <i>c.</i> 2 mm long, the connective narrowly conic-acute, the pollen sacs frontal and extending for about half the length of the connective on the ventral side, the dorsal gland elliptic and medially positioned; filaments not seen. Style 6-7 mm long; ovules 16. Fruits slightly oblong when immature but becoming globose, 6 mm in diameter, with persistent calycinal crown; epigynous chamber lacking radial partitions. REMARKS In Jacques-Félix (1985a), <i>M. perditum</i> would key to the group of species that includes <i>M. bernieri</i> Cogn., <i>M. peracuminatum</i> H.Perrier, and <i>M. bracteatum</i> Jacq. -Fél., on account of the anther connectives bearing a dorsal gland and the subsessile flowers each immediately subtended by a pair of bracts or bracteoles. The inflorescences of <i>M. perditum</i> appear most similar to those of <i>M. bracteatum</i>, except that in <i>M. bracteatum</i> the bracteoles subtending the central flower are larger (2.5 × 2 mm) and ovate to suborbicular (not lanceolate). The leaves of <i>M. bracteatum</i> are also very different in being lanceolate-acuminate (as are those of <i>M. peracuminatum</i>). <i>Memecylon bernieri</i> is like <i>M. perditum</i> in having leaves that are rounded at the apex, but its blades are narrowly oblanceolate (not obovate). The small, squamiform bracts and bracteoles of <i>M. bernieri</i> also differ from those of <i>M. perditum</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 page 346, DOI: 10.5281/zenodo.5187074