Trichilia congesta T.D.Penn., 2016

Pennington, Terence D., 2016, Systematic Treatment Of American Trichilia (Meliaceae), Phytotaxa 259 (1), pp. 18-162 : 92-93

40. Trichilia congesta T.D.Penn. spec. nov. (sect. Moschoxylum ). Type:— BRAZIL. Bahia, Municipio Ilheus, 2 km NNE of Banco da Vitoria, fl., Thomas, Jardim, Sant’Ana & da Paixão 10757 (holotype, K, isotypes NY). Plate 10 , Map 46

Trichiliae pseudostipularis affinis sed foliolis maximis, petiolo longo rhachidi excedente, inflorescencia congesta minima diffe rt.

Young shoots minutely appressed puberulous, soon glabrous, becoming cracked and thinly suberous, ca. 1 cm diam., dark brown with numerous raised white lenticels. Bud scales absent. Leaves pinnate, with or without a terminal leaflet, petiole 13–28 cm long, rhachis 9.5–27 cm long, petiole and rhachis semiterete, glabrous, petiolule of lateral leaflets 6–8 mm long, deeply channelled, petiolule of terminal leaflets up to 2 cm long. Leaflets opposite or subopposite, 6–7, lateral leaflets 32–38 cm long, 8–11 cm broad, terminal leaflet of similar size, all elliptic to oblong-elliptic, apex long narrowly attenuate, base acute or cuneate, coriaceous, glabrous, not glandular-punctate or -striate; venation eucamptodromous to brochidodromous, midrib flat or slightly raised on the upper surface; secondaries 19–24 pairs, shallowly ascending, arcuate, slightly convergent; intersecondaries absent; tertiaries forming a lax reticulum. Inflorescence cauliflorous and axillary, a densely congested panicle ca. 1.5 cm long, minutely puberulous to subglabrous; pedicel ca. 1.5 mm long. Calyx 1–1.25 mm long, 1.5–2 mm broad, rather fleshy, with 4 very shallow obtuse lobes, subglabrous. Petals 4, ca. 4 mm long, ca 0.75 mm wide, fused for ca. 2/3 of their length, valvate, lanceolate, apex acute, with a few minute hairs on the lobes, outside, otherwise glabrous. Staminal tube ca. 2.5 mm long, 1.5–2 mm broad, filaments completely fused, margin with 6 slender teeth alternating with the anthers and ca. 1/3 of their length, alternate filaments slightly shorter, glabrous outside, barbate in the throat; anthers 6, ca. 1 mm long, oblong, apex acute, base rounded, glabrous. Nectary absent. Ovary ca. 1 mm long, ovoid, 2–3-locular, locules with 2 collateral ovules, densely pubescent, style ca. 0.75 mm long, glabrous, style-head capitate with 2–3 minute acute lobes. Capsule ca. 1.5 × 1.3 cm, 3-valved, ovoid, apex acute, base rounded, smooth, shortly sericeous, pericarp ca. 1 mm thick. Seeds 2, ca. 1 × 0.6 cm, partly enclosed in a fleshy arillode which is developed only at the apex and along the adaxial surface, free apart from attachment from micropyle to raphe and strongly prolonged at the apex; seed coat thin, membraneous. Embryo with plano-convex, collateral cotyledons, radicle apical, extending to the surface. Endosperm absent.

MAP 46. Distribution of Trichilia congesta T.D.Penn. Total distribution to 2010.

Field Characters. Small treelet 1–5 m high, flowers with reddish calyx and pinkish corolla; fruit green, the seed with a brilliant orange arillode. Flowering is recorded in January and May. Mature fruit in November.

Distribution & Ecology. Confined to the wet lowland rain forests of coastal Bahia, Brazil, where it is a small understorey treelet. Occuring up to 500 m elevation.

Collections Examined. BRAZIL. Bahia: Santa Luzia Una, 11.3 km E do Sede de Municipio “Serra da Onca” (SW1539), Amorín et al. 2435 (NY); Municipio Jussarí, Jussarí-Palmira, 7.5 km E of Jussarí (SW1539), Amorím et al. 2583 (NY); Mun. Urucuca, 7.3 km N of Serra Grande on road to Itacoré (SW1439), Carvalho et al. 3402 (NY), Thomas et al. 9203 (NY); Municipio Ilheus, 2 km NNE of Banco da Vitoria (SW1439), Thomas et al. 10757 (K, NY).

Relationships. A very distinct species related to T. pseudostipularis , which shares a similar inflorescence and floral size and structure. It differs from the latter in its cauliflorous habit, in lacking the reduced basal leaflets and in the larger leaflets and generally in its leaflet shape (those specimens of T. pseudostipularis with large leaves have subsessile leaflets with a rounded base), and in the more numerous secondary veins. The seed and arillode structure is similar in both species. The ITS analysis place it closest to two other coastal Brazilian species, T. florbranca and T. magnifoliola .

Figures

PLATE 10. Trichilia congesta T.D.Penn. A, habit; B, detail of leaf undersurface; C, inflorescence; D, whole flower; E, half flower; F, detail of anthers; G, cross-section of ovary; H, infructescence; I, seed. (A, B, Carvalho et al. 3402; C, Alves et al. 1955; D–G, Thomas et al. 10757; H, I, Amorim et al. 2583).