Cecropia
Description
Trees, terrestrial, usually with stilt-roots; internodes hollow. Scars of the stipules transverse; petiole mostly with trichilia at the base; blade peltate, radially incised, main venation radial. Inflorescences digitate clusters of spikes, initially enveloped by a spathe, interfloral bracts absent. Perianth tubular; stamens 2; stigma penicillate to peltate. Fruit small, achene-like, endosperm present; cotyledons flat.
Distribution
Guianas present, Neotropics present
Neotropics approx. 100 species; in the Guianas 8 species known (a ninth one expected to occur).
Common Name
English: boesipapaja, bois canon, bospapaja, congo pump, diapapaia, diapapaye, manboesipapaja, soro-soro, trumpet tree, wana-soro
Wood
Vessels diffuse, solitary (50-820/o) and in radial multiples and irregular clusters of 2-3(5), round to oval, 1-3 per sq. mm, diameter 155-300 μm. Vessel-member length: 500-690 μm. Perfora-tions simple. Intervascular pits alternate, round or polygo-nal, 12-18 μm. Vessel-ray and vessel- parenchyma pits larger, elongated, occasionally sligthly opposite, half- bordered. Thin-walled tyloses present or absent.
Rays uniseriate and 2-6-seriate, 3-7 per mm, up to 1000-2200 μm high. Heterogeneous, composed of procumbent, upright and square cells, with uniseriate margins of 1-4 rows. Occasionally vertically compound. Rhom- bic crystals present or absent. Radial latex tubes scarce.
Parenchyma scarce, paratracheal, vasicentric to aliform, sometimes confluent; sometimes apotracheal terminal bands. Strands of 4-6 cells. Rhombic crystals occasionally present.
Fibres non-septate, lumen 26-50 μm, walls 2-4 μm. Pits simple, small, mainly on the radial walls. Gelatinous fibres scarce. Length: 1100-2100 μm. F/V ratio: 2.2-3.5.
Rays uniseriate and 2-6-seriate, 3-7 per mm, up to 1000-2200 μm high. Heterogeneous, composed of procumbent, upright and square cells, with uniseriate margins of 1-4 rows. Occasionally vertically compound. Rhom- bic crystals present or absent. Radial latex tubes scarce.
Parenchyma scarce, paratracheal, vasicentric to aliform, sometimes confluent; sometimes apotracheal terminal bands. Strands of 4-6 cells. Rhombic crystals occasionally present.
Fibres non-septate, lumen 26-50 μm, walls 2-4 μm. Pits simple, small, mainly on the radial walls. Gelatinous fibres scarce. Length: 1100-2100 μm. F/V ratio: 2.2-3.5.
Notes
In early juvenile stages the blades are basally attached, elliptic and entire with pinnate venation. Next they become broadly elliptic to ovate and palmately incised with palmate venation, and finally peltate with radiate incisons.
In most species one can find one or two patches of dense indument ("trichilia") at the base of the petiole. In these trichilia a special type of trichome is found. These trichomes form food bodies (Mullerian bodies) which constitute the main food source of the ants inhabiting the hollow internodes of the stem and branches. Another adaptation to the association with ants is the occurrence of a thin spot ("prostoma") in the wall of the internode, which can be easily perforated by ants e.g., colonizing queens).
In most species the anthers are detached from their filaments when they are pushed through the narrow, slit-shaped aperture of the perianth by elongation of the flat filaments. If the anthers are relatively large they remain connected to the filament by a bundle of stretched spiral thicken- ings of the tracheids of the vascular bundle of the filament (like inC. palmata ). If they are small then they become attached by sticky appendages of the thecae to the margin of the aperture of the perianth or less commonly to the upper margin of the filament.
In most species one can find one or two patches of dense indument ("trichilia") at the base of the petiole. In these trichilia a special type of trichome is found. These trichomes form food bodies (Mullerian bodies) which constitute the main food source of the ants inhabiting the hollow internodes of the stem and branches. Another adaptation to the association with ants is the occurrence of a thin spot ("prostoma") in the wall of the internode, which can be easily perforated by ants e.g., colonizing queens).
In most species the anthers are detached from their filaments when they are pushed through the narrow, slit-shaped aperture of the perianth by elongation of the flat filaments. If the anthers are relatively large they remain connected to the filament by a bundle of stretched spiral thicken- ings of the tracheids of the vascular bundle of the filament (like in