Cecropia angustifolia Trécul

Species Description

Tree, to 20(-25) m tall. Leafy twigs (1-)2-5 cm thick, green to brownish to often (turning) blackish, hispidulous to hirtellous to strigose to subvelutinous or to villous, usually also with dense brown to blackish pluricellular hairs, sometimes also with arachnoid indumentum; internodes with sparse (whitish) pith or sometimes partly to entirely filled with brown pith. Lamina chartaceous to coriaceous, ca. (20 × 20 cm to) 45 × 45 cm to 75 × 75 cm (to 90 × 90 cm), the segments (8-) 10-14, in young leaves often reflexed, the free parts of upper segments (ob)lanceolate to oblong to subobovate, the incisions down to (5/10-) 6/10-9/10 (or to near the petiole); apices obtuse to rounded or subacute to short-acuminate; upper surface scabrous or smooth, densely to sparsely hispidulous or puberulous or partly to hirtellous or to (sub)strigillose, also with ± dense brown pluricellular hairs and sometimes sparse arachnoid indumentum, the "umbilicus" sometimes villous; lower surface sparsely to densely (minutely) puberulous (with straight to uncinate hairs) to hirtellous to subtomentose or to subhirsute on the (main) veins, with arachnoid indumentum confined to the areoles, extending to the smaller veins, or (almost) absent; lateral veins in the free part of the midsegment (12-)15-35(-43) pairs, submarginally or marginally loop-connected, branched or unbranched; petiole 20-70 cm long, sparsely to densely puberulous to hirtellous to sub-hirsute or to villous, or sometimes also with sparse to dense arachnoid indumentum; trichilia fused, the brown indumentum intermixed with short (or sometimes rather long) white to brownish (unicellular) hairs; stipules 6-25(-30) cm long, caducous or subpersistent, green to yellowish, reddish to purplish, brownish or black, sparsely to densely white to brownish puberulous to hirtellous or partly to largely subhirsute to sericeous to subvelutinous or to villous, also with ± dense brown pluricellular hairs outside, sparsely to densely white- to pale brown-sericeous (or glabrous) inside. Staminate inflorescences in pairs, erect, often subtended by subpersistent bracts, to 5 cm long; peduncle 1-8(-12) cm long, puberulous to sub-hispid to hirtellous to subhirsute or to subvelutinous and often (initially) with dense brown pluricellular hairs and often also sparse arachnoid indumentum, sometimes subglabrous; spathe 4-14 cm long, greenish to yellowish to brownish or reddish to purplish, densely white- to brownish-puberulous to -hirtellous or partly to -subhirsute to -strigose or to villous and with dense brown pluricellular hairs or also with sparse to rather dense arachnoid indumentum outside, sparsely to densely (sub)sericeous or glabrous inside; spikes 10-25(-50), (1.5-)3-l 1(-13) × 0.3-0.8 cm, sessile or with stipes to 0.7(-1.2) cm long, (sub)glabrous to puberulous to hirtellous; rachis hairy (or glabrous). Staminate flowers: perianth tubular, 12 mm long, with short and stiff hairs on the ribs, arachnoid indumentum below the apex, or glabrous, the apex plane to convex, smooth or muriculate, the aperture circular or slit-shaped; filaments flat or ± swollen; anthers 0.5-0.9 mm long, appendiculate or not, detached and reattached to the margins of the aperture by the appendages or remaining attached to the filament at anthesis. Pistillate inflorescences in pairs, erect, often subtended by subpersistent bracts, to 3 cm long; peduncle 1-8(-12) cm long, the indumentum as in the staminate inflorescence; spathe 3-6(-8) cm long, color and indumentum as in the staminate inflorescence; spikes 3-8(-12), 1-7 × 0.4-0.8 cm, to 17 X 0.8-2 cm in fruit, often broadened toward the base, sessile; rachis hairy (or glabrous). Pistillate flowers: perianth 1.5-2.5 mm long, with arachnoid indumentum below the apex outside, also in the lower part of and/or below the style channel inside, the apex convex to almost plane, muriculate to minutely hispidulous or glabrous, the aperture circular or slitshaped; style rather short; stigma comose. Fruit ellipsoid to oblongoid to ovoid 1.5-2.5 mm long, tuberculate or smooth.

Discussion
This species is highly variable not only morphologically but also ecologically, considering the wide elevational range inhabited and the occurrence in relatively dry habitats in some regions and in very wet habitats in others. Attempts to distinguish (at least at the subspecific level) formal entities related to distribution and ecology have failed, partly because of the rather confusing patterns in the morphological differentiation and partly because of lack of sufficient collections from many parts of its range of distribution. But it is possible to recognize some more or less distinct informal entities, representing extremes of the variation.

In material from Venezuela and the eastern Cordillera in Colombia, southward to Caqueta, and from the Sierra de la Macarena, the indumentum is (rather) sparse and the upper surface of the lamina is usually smooth. The lamina is usually coriaceous to subcoriaceous, and the reticulum veinlets are often thick, and, therefore, the areoles small beneath. This material includes the types of Cecropia coriacea, C. moniquirana, C. palmatisecta, and C. philipsonii.
Another type is found in the western part of Colombia from Antioquia to Nariño and adjacent Ecuador (Carchi). It is largely associated with relatively dry areas in the western Cordillera, the Cauca Valley, and parts of the central Cordillera. It is distinctly hairy (hirtellous to subtomentose) on the veins of the lamina beneath, scabrous above, and at least in the southern and northern part of its range of distribution often without arachnoid indumentum in the areoles of the lamina beneath. This type is most clearly represented by the material described as Cecropia caucana and C. danielis, but it also includes the type material of C. strigilosa. In the Cauca Valley the stipules and spathes are usually reddish to purplish, and the pistillate inflorescences can be ± pendulous at fruit, due to relatively long peduncles. South of the Cauca Valley (Nariño and adjacent Ecuador) the stipules and spathes are greenish to yellowish, the peduncle of the pistillate inflorescences is short, the arachnoid indumentum in the areoles is often lacking, the internodes can be completely filled by brown pith, and the number of lamina segments is relatively small, mostly 89, as in the type of C. caucana. In (northern) Antioquia (as in the type of C. danielis), the smaller veins of the lamina are often prominent beneath, whereas normally (almost) plane, the arachnoid indumentum is often lacking in the areoles of the lamina beneath, but in contrast to the material occurring south of the Cauca Valley, the number of lamina segments is 911. In adjacent wetter parts of Colombia and Ecuador, the lamina has usually 11-13 segments and the indumentum on the veins beneath is short and inconspicuous.
On the eastern slopes of the Andes, from Caqueta to Morona-Santiago, three morphological types can be distinguished. One of them resembling the type of the wetter parts in western Colombia and Ecuador, a second one with relatively few (ca. 9) lamina segments and densely hairy, sericeous to subhirsute on the stipules and often also on the spathes, and a third one (only found in Caqueta) with rather dense arachnoid indumentum on the leafy twigs and the petioles. The second type has been described as Cecropia hachensis and occurs in two color morphs, at least in parts of its range of distribution: a green morph and a reddish to purplish one.
Material in the coastal region of Ecuador, in El Oro and Manabi, at 550-1500 m, shows similarities to Cecropia montana in the whitish stipules and spathes and in the presence of rather long white unicellular hairs in the trichilia, but the number of lateral veins in the free part of the midsegment is up to ca. 20 pairs, thus distinctly less than the minimum number in C. montana.
In the southern part of the species range at least three types can be recognized. The most prominent one is found in Bolivia and adjacent Peru. It has blackish and subpersistent stipules and incisions down to ca. 6/10-7/10 or incisions down to near the petiole. More northward in Peru, the stipules vary in color from brown to greenish and are either caducous or subpersistent. The latter type comprises the type of the species. In some specimens from Bolivia and Peru (as in the type of the species) the lamina has narrow segments, to 4 cm broad in medium-sized leaves. In Bolivia (Cochabamba) a purplish morph occurs besides the predominant green morph. In the majority of the material from Peru, the number of lateral veins in the free part of the midsegment varies from ca. 23 to 35 pairs, but in the third type the number varies between 15 and 20 pairs. The third type is represented by Berg et al 1632, 1750, and 1753, the latter two found at ca. 400 m.
A remarkable type is represented by material from southern Ecuador and northern Peru on the eastern slopes of the Andes and from Costa Rica and western Panama. Material from Ecuador was recently described as Cecropia villosa (Berg & Franco Rosselli, 1993). Although in general features quite similar to C. angustifolia, it is distinct in villous indumentum and internodes entirely filled with brown pith. Further studies on the genus revealed that this material did not differ clearly from collections from Costa Rica which were named C. polyphlebia and were made from trees not inhabited by ants (Longino, 1989a); the Ecuadorian trees are also not occupied by ants. Ants are absent in spite of the common presence of trichilia, producing abundant Mullerian bodies (cf. Janzen, 1973: 17, fig. 1). The absence of ants is likely caused by the ample pith in the internodes. In C. angustifolia the pith in the internodes is usually very sparse, rarely ample (as in Berg et al. 1759). The unusual disjunction between two sets of specimens and the fact that they fill gaps in the distribution of C. angustifolia led finally to the decision to include the material initially recognized as C. polyphlebia and C. villosa in C. angustifolia. This villous type tends to have more lateral veins [ca. 25-35(-40) pairs] in the free part of the midsegment of the lamina than is usual in C. angustifolia. It is remarkable not only that this villous type with ample pith arose disjunctly, but also that both in Ecuador and Central America it is morphologically linked to a hairy type without ample pith. In Ecuador, this type includes the type of C. hachensis, and in Central America it is represented by collections with mostly brownish indumentum from Nicaragua and Honduras.
This species is closely related to Cecropia montana. The differences between the two species are discussed under the latter.

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