Cecropia obtusa Trécul

Species Description

Tree, to 12(-25) m tall. Leafy twigs 1-5 cm thick, green, hispidulous with curved hairs. Lamina chartaceous to (sub)coriaceous, ca. 25 × 25 cm to 60 × 60 cm, the segments 6-8(-9), the free parts of the upper segments usually obovate to subobovate, sometimes to subspathulate, the incisions down to 5/10-7/10(-8/ 10); apices obtuse to subacute (short-acuminate); upper surface ± scabrous or smooth, (very) sparsely to rather densely hispidulous and with ± dense arachnoid indumentum; lower surface puberulous to pubescent on the veins, with arachnoid indumentum in the areoles, extending to the main veins; lateral veins in the free part of the midsegment 9-15 pairs, sub-marginally loop-connected, unbranched or faintly branched; petiole 15-50 cm long, puberulous to pubescent and with ± dense (persistent) arachnoid indumentum; trichilia fused, the brown indumentum intermixed with short and/or rather long white hairs; stipules 7-12(-20) cm long, dark to bright red or grayish when covered by dense arachnoid indumentum, puberulous to hirtellous to strigillose and usually also with sparse to dense arachnoid indumentum outside, (sub)sericeous inside. Staminate inflorescences in pairs, the peduncle erect and the spikes pendulous; peduncle 4-8.5 cm long, hispidulous or partly pubescent; spathe 8-17 cm long, red-brown to yellowish or whitish, puberulous to hirtellous and with sparse to dense arachnoid indumentum outside, glabrous inside; spikes 15-26, 4-13 0 × 0.2-0.3 cm, with stipes 0.5-1.5 cm long and densely minutely puberulous; rachis hairy. Staminate flowers: perianth 1-1.5 mm long, minutely puberulous with straight hairs or also with arachnoid indumentum below the margin, the apex plane to slightly convex or truncate, muriculate, the aperture often surrounded by a rim; filaments slightly swollen; anthers 0.5-0.7 mm long, appendiculate, detached at anthesis, reattached to the margins of the aperture by the appendages (?). Pistillate inflorescences in pairs, erect; peduncle 6.5-8(-14) cm long, hispidulous or partly pubescent; spathe 8-12 cm long, the color and indumentum as in the staminate inflorescence; spikes 4, 3-10 × ca. 8 cm, to 16 × 1.5 cm in fruit, sessile or with stipes to 0.8 cm long and minutely puberulous or also with arachnoid indumentum; rachis hairy. Pistillate flowers: perianth ca. 2 mm long, with arachnoid indumentum below the apex outside, also below the style channel inside, the apex convex, densely muriculate; style rather long, straight; stigma comose. Fruit oblongoid to ellipsoid, ca. 2.5 mm long, ± tuberculate.

Discussion

The species appears to be closely related to the allopatric Cecropia ficifolia. The two species have many features in common. Cecropia obtusa differs from C. ficifolia, e.g., in the larger number of spikes in the staminate inflorescence, the shorter peduncle of the pistillate inflorescence, and the shorter stipules. If the lamina is deeply incised (5/10), then the free part of the midsegment is ± abruptly narrowed and thus ± distinctly spathulate, whereas usually obovate to subobovate and rarely subspathulate in C. obtusa. In C. obtusa, the petiole is covered with persistent arachnoid indumentum. When such indumentum occurs in C. ficifolia (as in Ecuador and Colombia), it is (often) in combination with hirsute indumentum. Whereas C. ficifolia is a weedy species, at least in part of its range of distribution, C. obtusa is associated with forest habitats.

The following collection is difficult to interpret: Serra do Navio, Rio Amapari, 12 Nov 1954 ([female] fr), Cowan 38280 (NY, US). The label indicates that it is made from a tree 5 m tall, unlikely for this species to be already in fruit; the inflorescences are separate from the partial leaf, which has narrow segments with up to ca. 25 pairs of lateral veins in the free part of the midsegment, and the arachnoid indumentum is dense in the petiole but sparse on the lamina and absent in the areoles beneath. It is difficult to relate the leaves to the juvenile state of C. obtusa.
The name Cecropia obtusa was based on four collections: the present lectotype, Bonpland 1295 from Cuba (= C. schreberiana subsp. antillarum), Gardner 3981 (= C. saxatilis), and Ruiz & Pavón s.n. (= C. polystachya).

Authority

Berg, Cornelius C. & Franco Rosselli, Pilar. 2005. Cecropia. Fl. Neotrop. Monogr. 94: 1--230. (Published by NYBG Press)