Trichilia tenuifructa T.D.Penn., 2016

Pennington, Terence D., 2016, Systematic Treatment Of American Trichilia (Meliaceae), Phytotaxa 259 (1), pp. 18-162 : 129-131

68. Trichilia tenuifructa T.D.Penn. spec. nov. (sect. Moschoxylum ). Type:— PERU. Loreto, Prov. Requena. Distrito Sapuena, basin of R. Ucayali, Jenaro Herrera and vicinity, 3 km E of Jenaro Herrera town, 2 km NE of Centro de Investigaciones Jenaro Herrera, fl., September. 1989, Daly, Bennett, Mozombite, Pacaya, Vilchez, Maytehuari & Valcarcel 6223 (holotype, K; isotype, NY). Plate 15 , Map 77

Trichiliae poeppigii affinis sed foliolorum costa prominente, floribus petalis liberis, et capsula ad basin et extremum multum prolongata differt.

Young shoots sparsely and minutely appressed puberulous with dibrachiate hairs, soon glabrous, becoming dark brown, scaling and cracked, 3–7 mm diam., usually sparsely lenticellate. Bud scales absent. Leaves pinnate, sometimes with 1 leaflet orientated to simulate a terminal leaflet, petiole 3–6 cm long, rhachis 5.5–10 cm long, petiole and rhachis semiterete, glabrous; petiolule 3–8 mm long, slightly channelled. Leaflets alternate, 5–6, 9.5–16 cm long, 3.6–7.1 cm wide, elliptic, apex acuminate, base narrowly attenuate, chartaceous, glabrous, not glandular-punctate or -striate; venation eucamptodromous or sometimes brochidodromous in the upper half, midrib sharply raised on the upper surface; secondaries 9–12 pairs, ascending, arcuate, slightly convergent; intersecondaries usually present, moderately developed; tertiaries forming a lax reticulum. Inflorescence axillary, 10–20 cm long, a narrowly pyramidal panicle, the lower branches to 6 cm long, glabrous; pedicel ca. 1 mm long. Calyx ca. 0.5 mm long, ca. 2 mm broad, patelliform, very shallowly and obtusely 4-lobed, with scattered minute appressed hairs outside. Petals 4, ca. 4 mm long, 1–1.25 mm wide, free, valvate, lanceolate or narrowly triangular, apex acute, glabrous. Staminal tube ca. 3 mm long, ca. 1.5 mm wide, filaments completely fused, margin with 8 slender teeth alternating with the anthers and ca. 1/2 their length, glabrous; anthers 8, ca. 0.8 mm long, oblong, glabrous. Nectary absent. Ovary ca. 1.75 mm long, conical, 3-locular, locules with 2 collateral ovules, shortly pubescent, style ca. 0.5 mm long, glabrous, style-head capitate, scarcely expanded. Capsule 4.5–5.5 cm long, 1–1.4 cm wide, 3-valved, slender ellipsoid and narrowly attenuate to apex and base, smooth, minutely and densely appressed puberulous, pericarp ca. 0.75 mm thick. Seed solitary, ca. 1.8 x 0.7 cm, narrowly obovoid, apex rounded, base acute, partly enclosed in a free thin fleshy arillode which is greatly developed at the apex into a slender prolongation equalling the length of the seed, arillode free except for attachment from micropyle to raphe and covering most of the seed surface except for a small area at the base; arillodes also develop around the aborted ovules; seed coat thin, membraneous; embryo with plano-convex, collateral cotyledons, radicle apical, included. Endosperm absent.

Field Characters. Small tree to 18 m high and 17 cm diam, with brown bark scaling in longitudinal strips. Flowers with greenish-cream, reflexing petals and white staminal tube; fruit greenish. Flowering recorded February in Venezuela, in July in central Brazilian Amazonia and August to October in Peruvian Amazonia. Fruit maturing February to March throughout its range.

Distribution & Ecology. Amazonian Peru, central Brazilian Amazonia and southern Venezuela. A species of lowland rain forest below 300 m elevation, recorded from well-drained sandy soils, alluvial terraces and occasionally also in swampy areas.

MAP 77. Distribution of Trichilia tenuifructa T.D.Penn. Total distribution to 2010.

Collections Examined. VENEZUELA. Territorio Federal Amazonas: Atabapo, upper R. Orinoco, Caño Libreta (NW0265), Aymard & Delgado 7844 (K); Upper R. Orinoco (NW0365), Aymard & Delgado 8402 (K).

PERU. Loreto: Prov. Requena, Jenaro Herrera (SW0473), Bernardi 16283 (G); Daly et al. 6206 (K), 6219 (K), 6223 (K); Diaz 40-A (G); Prov. Maynas, Puerto Almendras (SW0373), Vásquez & Jaramillo 2601 (K); Prov. Requena, without exact locality (SW0473), van der Werff et al. 10069 (F, K).

BRAZIL. Amazonas: Distrito Agropecuario, Fazenda Porto Alegre, Reserva 3304 WWF/INPA MCS project (SW0259), Pacheco et al. 214 (K, US); Manaus-Itacoatiara km 26, Ducke Forest Reserve (SW0259), Ribeiro et al. 1049 (K).

Local names. Requia blanca, requia fruto largo ( Peru).

Relationships. Trichilia tenuifructa was tentatively placed within T. poeppigii in the Flora Neotropica account (FN28: 165 (1981), but now that flowering material is available, it is clear that it represents a distinct species. It differs from T. poeppigii in the sharply raised leaflet midrib (flat or only slightly raised in T. poeppigii , in the free, reflexing, glabrous petals (fused to at least half their length, erect, with appressed indumentum in T. poeppigii ), and in the long, slender capsule which is produced at both ends, and in the unusual structure of the arillode which is strongly developed and produced at the apex to form a structure equalling the length of the seed.

Trichilia tenuifructa is also close in floral structure to T. schomburgkii , but it lacks the reduced basal leaflets of that species, and their fruit and arillode structure are distinctive. The ITS data places it closest to T. schomburgkii .

Figures

PLATE 15. Trichilia tenuifructa T.D.Penn.A, habit with inflorescence; B, detail of leaf undersurface; C, whole flower; D, half flower; E, cross-section of ovary; F, infructescence; G, seed with arillode. (A–B, van der Werff et al. 10069; C–E, Daly et al. 6219; F, G, Pacheco et al. 214).