Oraniopsis (Becc.) J.Dransf., A.K.Irvine & N.W.Uhl, Principes 29: 57 (1985)Protologue

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Description

  • Medium, solitary, unarmed, pleonanthic, dioecious palm. Stem erect, sometimes quite tall, becoming bare, leaf scars apparently not very conspicuous. Leaves numerous, reduplicately pinnate, ± upward-pointing, marcescent, several dead leaves hanging vertically for some time, forming a skirt below the crown before falling completely; sheath apparently tubular at first, soon splitting opposite the petiole, the leaf base then open; petiole short, adaxially channelled, ± glabrous, abaxially rounded, densely covered with scales and tomentum, the margins smooth and rather sharp; rachis ± stiffly held, adaxially flattened or channelled near the base, abaxially rounded, distally angled adaxially, a minute flange present at the junction between the flattened and angled areas of the rachis, both surfaces of the rachis bearing scattered scales; leaflets very numerous, single-fold, regularly arranged, ± stiff, ± linear, unevenly acute or acuminate, the basal-most few on each side short, narrow and crowded, adaxial surface ± glabrous or with scattered scales along the midrib, abaxial surface covered with dot-like scales and a dense felt of indumentum; transverse veinlets not evident. Inflorescences solitary, axillary, interfoliar, shorter than the leaves, staminate and pistillate superficially similar, branching to 4 orders; prophyll short, obscured by the leaf bases, incompletely tubular, 2-keeled, ± leathery, becoming fibrous and disintegrating distally, sparsely tomentose, the basal margins decurrent; peduncle elongate ± flattened and winged at the base, distally ± elliptic in cross-section, sparsely to densely tomentose; peduncular bracts 3–5, elongate, the first inserted near the prophyll, the rest ± evenly spaced along the peduncle, the distal 2–3 ± enclosing the inflorescence in bud, ± beaked, leathery, tubular at first, then splitting longitudinally and becoming flattened, sparsely to densely tomentose, eventually caducous, leaving circular or crescentic scars; rachis slightly shorter than the peduncle; rachis bracts numerous, inconspicuous, short, triangular, acute or acuminate, membranous, incomplete, each subtending a first-order branch; first-order branches with a basal bare portion, distally bearing spirally arranged second-order branches each subtended by a minute incomplete bract; rachillae crowded, ± twisted or zigzag at anthesis, the pistillate spreading but remaining rather zigzag in fruit, bearing rather distant, spirally arranged or subdistichous, minute triangular bracts, each subtending a short stalk bearing a minute, membranous, incomplete, triangular bracteole and terminating in a solitary flower. Staminate flowers symmetrical, or somewhat misshapen from close packing, open from early in development; sepals 3, very small, triangular, membranous, connate basally and forming a cup; petals 3, distinct, fleshy, much longer than the sepals, narrow, triangular; stamens 6, almost as long as or longer than the petals, the antesepalous inserted between the petals in, apparently, the same whorl, the antepetalous epipetalous, filaments very fleshy with ± conical, swollen bases, tapering to the connective, anthers oblong, versatile, basally sagittate, latrorse; pistillode usually very much shorter than the filaments, 3-angled, apically trifid. Pollen ellipsoidal, slightly asymmetric; aperture a distal sulcus; ectexine tectate, foveolate, aperture margin broad scabrate and finely perforate; infratectum columellate; longest axis ranging from 33–40 µm [1/1]. Pistillate flowers like the staminate but with slightly broader sepals and petals; staminodes like the stamens, the empty anthers large; gynoecium tricarpellate, triovulate, conspicuously 3-lobed, stigmas apical, short, becoming recurved; ovules laterally attached, ?hemianatropous. Fruit developing from 1 carpel, rounded, the stigmatic and carpel remains basal; epicarp smooth, yellow at maturity; mesocarp ± fleshy, with horizontal fibres and stone cells; endocarp obsolescent. Seed, rounded, the integuments thick, ± woody, with a basal short spur, and few sparsely branched, impressed vascular strands; endosperm homogeneous with a narrow central hollow; embryo lateral to subbasal. Germination adjacent-ligular; seedling leaf bifid with entire tips. Cytology not studied. (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)

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Bibliography

A. J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008
B. World Checklist of Arecaceae