Lepidorrhachis (H.Wendl. & Drude) O.F.Cook, J. Heredity 18: 408 (1927)

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  • Small to moderate, solitary, unarmed, pleonanthic, monoecious palm. Stem thick, short, green, prominently ringed with close leaf scars. Leaves pinnate, ascending; sheath inflated at the base, deeply split opposite the petiole, not forming a distinct crownshaft, densely brown-scurfy toward the apex and petiole; petiole short, shallowly channelled adaxially, rounded abaxially, densely brown-scurfy; rachis adaxially channelled to ridged, abaxially rounded, densely tomentose; leaflets regularly arranged, alternate, single-fold, acute, stiff, ascending from the rachis, the midrib and 2–3 secondary nerves on each side prominent adaxially, margins thickened, bearing scales along ribs on both surfaces, transverse veinlets not evident. Inflorescences apparently unisexual, interfoliar in bud, becoming infrafoliar at anthesis, branched to 3 orders basally, fewer distally, densely covered with basifixed, twisted, simple to forked or tattered, brown, membranous scales; peduncle very short; prophyll usually incompletely sheathing, 2-keeled, open apically, apparently completely encircling at the base; peduncular bract tubular, beaked, exserted from the prophyll; rachis longer than the peduncle, bearing short, wide, acute bracts subtending rather distant, spirally arranged branches and rachillae; rachillae short, bearing paired or solitary staminate flowers or solitary pistillate flowers, the flowers superficial, each subtended by an acute bract. Staminate flowers slightly asymmetrical; sepals 3, distinct, imbricate basally, keeled, ± rounded apically; petals 3, distinct, slightly asymmetrical, about twice as long as the sepals, strongly nerved when dry; stamens 6, filaments distinct, inflexed in bud, anthers oblong in outline, latrorse; pistillode narrowly cylindrical, expanded apically, slightly longer than the stamens in bud. Pollen grains ellipsoidal asymmetric, occasionally lozenge-shaped; aperture a distal sulcus; ectexine tectate, perforate and micro-channelled, aperture margin similar or slightly finer; infratectum columellate; longest axis 32–44 µm [1/1]. Pistillate flowers symmetrical; sepals 3, distinct, broadly rounded and imbricate; petals 3, distinct, imbricate with briefly valvate apices, strongly nerved when dry; staminodes 3, on one side of the gynoecium; gynoecium unilocular, uniovulate, subglobose, stigmas recurved, ovule pendulous, probably hemianatropous. Fruit globose or nearly so, red at maturity, stigmatic remains lateral in the upper 1/3–1/4; epicarp smooth, drying granular over included sclerosomes, mesocarp fleshy, thin, with included longitudinal fibres except along the rapheal region, endocarp thin, fragile, operculate. Seed globose, with elongate raphe, hilum apical, short, elliptic, vasculature prominent, branched, the branches anastomosing abaxially, endosperm homogeneous; embryo subbasal. Germination and eophyll unrecorded. 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)A

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