Trichilia tomentosa Kunth

Pennington, Terence D., 2016, Systematic Treatment Of American Trichilia (Meliaceae), Phytotaxa 259 (1), pp. 18-162 : 44-46

6. Trichilia tomentosa Kunth in Humboldt, Bonpland & Kunth, Nov. Gen. Sp. 5: 215 (1822); C.DC., Monogr. Phan. 1: 666 (1878) ; Harms. Fedde. Rep. 19: 56 (1923); T. D. Penn., Fl. Neotrop. 28: 63, fig. 6 (1981) ; W. Palacios, Fl. Ecuador 82: 85 (2007). Type :— PERU. Cajamarca, between Cotumasey and Trujillo, fl., Humboldt & Bonpland s.n. (holotype, P-Bonpl.). Map 9

Young branches stout (ca. 1 cm diam.), coarsely pubescent, becoming glabrous, rough, greyish-brown with a few lenticels, and prominent leaf and bud scale scars. New growth subtended by a small cluster of oblanceolate or oblong, pubescent buds scales 4–9 mm long. Leaves imparipinnate, petiole 5–8.5 cm long, semiterete, coarsely pubescent, becoming glabrous with age, rhachis 14–18(–22.5) cm long, semiterete, sparsely pubescent to glabrous; petiolule of lateral leaflets 1–2 mm long, petiolule of terminal leaflet 1–1.5 cm long. Leaflets opposite, 5–8 pairs, lateral leaflets 8 x 2.5–11.5(–13) × 4.5 cm, lanceolate to oblong-elliptic, apex narrowly acuminate, base usually slightly asymmetric, acute one side and obtuse to rounded the other; lateral leaflets decrease in size towards the base of the leaf; terminal leaflet 6.5 x 2.5–11.7 × 4 cm, elliptic, apex acuminate, base regular, narrowly attenuate, chartaceous, upper surface sparsely pubescent along the midrib, lower surface uniformly pubescent to tomentose, usually denser on the veins, finely glandular-punctate and -striate or not; venation eucamptodromous, midrib sunken on the upper surface, secondaries 12–22 pairs, ascending, straight or slightly arcuate, parallel or slightly convergent; intersecondaries absent; tertiaries reticulate. Inflorescence axillary, clustered at the shoot apex, a panicle with cymose branches, 10–20 cm long, peduncle 3–7 cm long, lateral branches 2–6 cm long, sparsely pubescent; pedicel 1–1.5 mm long (above the articulation), bracts 1–2 mm long, lanceolate, pubescent, caducous. Flowers unisexual (plant dioecious). Female flowers only seen. Calyx 1–1.5 mm long, patelliform, sepals 5, +/- free, ovate, apex acute, aestivation open or slightly imbricate at the base, stiffly pubescent outside, glabrous inside. Petals 5, 6–8 mm long 1.5–2 mm broad, free, imbricate, strap-shaped, apex acute, with scattered coarse pubescence outside, pubescent or +/- glabrous inside. Staminal tube 4–6 mm long, ca. 2 mm broad, cylindrical, filaments fused for 1/2 to 2/3 of their length, filament apex entire or with 2 short teeth, rounded or truncate, glabrous below and coarsely pubescent in the upper half on both surfaces; antherodes 10, 0.75–1 mm long, lanceolate, not dehiscent, without pollen. Nectary an annulus around the base of the ovary, glabrous. Ovary ca. 3 × 2 mm, ovoid, 3-locular, locules with 2 collateral ovules, coarsely pubescent, style 1.5–2 mm long, pubescent, style-head capitate. Capsule 1–1.5 cm long, 0.9–1.7 cm broad, 3-valved, subglobose to slightly 3-lobed on drying, apex truncate, base rounded, smooth (wrinkled on drying), glabrous, drying dark-brown with numerous pale lenticels; pericarp ca. 0.75 mm thick. Seeds 3–6, 1–2 collateral in each valve, 7–9 mm long, rounded at apex and base, sometimes plano-convex when 2 collateral in a valve, with a fleshy, free, oily arillode covering the upper third of the seed. Embryo with thick, plano-convex, collateral cotyledons, radicle apical, slightly exserted, endosperm absent.

MAP 9. Distribution of Trichilia tomentosa Kunth. Solid dots, distribution pre-1981, open dots new records 1981–2010.

Field Characters. Small tree to 15 m high and 30 cm dia., with pale brown bark scaling in irregular plates and a dense round crown; slash pinkish or cream-coloured, without scent. Leaves clustered at branch tips. The flowers have pale green petals and cream stamens. The fruit matures dark brown with numerous pale lenticels, but the inner surface of the pericarp is almost white, and the seed black and shiny, with an orange arillode. Flowering occurs in November. and the fruit matures from March to June.

Distribution & Ecology. Occuring only in southern Ecuador and northern Peru where it is a component of seasonally dry, mostly deciduous forest between 1350 and 2550 m elevation.

Collections Examined. ECUADOR. El Oro: ca. 60 km W of Loja (SW0379), Pennington & Tenorio 10723 (K). Loja: Sozoranga, Cuesta de San Fernando (SW0478), Palacios 3317 (NY).

PERU. Cajamarca: between Cotumasey and Trujillo (SW0778) Humboldt & Bonpland s.n. (P-Bonpl.); Rupe- Contumaza (SW0778), Sagástegui et al. 9811 (K); Vista Alegre, Asunción (SW0778), Sagástegui et al. 10144 (K); Prov. Contumaza, 11 km N of Contumaza, road to Chilete (SW0778), Stein & Todzia 2046 (K); Magdelena to Caja Mayo (SW0778), Weberbauer 7222 (F. S). Piura: District Huarmaca, Limón (SW0579), Gonzalez 753 (K); Prov. Huancabamba, Olmos to Porcuya km 38 (SW0579), Pennington et al. 12322 (K, MOL), Pennington & Daza 16870 (K, MOL); Olmos to Porculla, km 34 (SW0579), Pennington & Daza 18400 (K, MOL), 18401 (K, MOL); Prov. Huancabamba, above Canchaque (SW0580), Pennington et al. 12329 (K. MOL), Diaz et al. 3177 (MOL, NY); District Huarnaca, Limon-Chuspi-Pirca (SW0579), Timana 301 (K, MOL), 310A (K, MOL).

Relationships. Trichilia tomentosa is closely related to both T. multifoliola ( Bolivia) and T. dazae (N. Peru). It differs from both by the uniformly pubescent or tomentose lower leaflet surface and by the indumentum on the young shoots and inflorescence. It also differs from T. multifoliola in having generally fewer pairs of leaflets and in the greater fusion of its staminal filaments (to approx. two thirds of their length). It also differs from T. dazae in its flower colour (petals pale green versus pink in T. dazae ). All three species are also close to the widespread T. hirta , but they differ from the latter in their larger flowers, +/- free sepals, glabrous fruit, and arillode structure.