Carpoxylon H.Wendl. & Drude, Linnaea 39: 177 (1875)

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Number of Taxa

  • 1 species

Discussion

Biology And Ecology

Common Name

Etymology

Diagnosis

Description

  • Moderate, solitary, unarmed, pleonanthic, monoecious palm. Stem erect, longitudinally fissured, swollen basally and with a boss of adventitious roots, distally prominently ringed with slightly sunken leaf scars, internodes short. Leaves regularly pinnate, spreading but arched towards the tips, neatly abscising; sheaths forming a crownshaft, sheaths glossy, glabrous to lightly scaly, splitting opposite the petiole; petiole short, tapering distally, ridged adaxially, rounded abaxially; rachis flexible, broadly ridged adaxially at base, narrowly ridged distally, rounded abaxially, extended beyond the apical leaflets in a flexible tip; leaflets regularly arranged, single-fold, erect, linear, tapering to an irregularly rounded, ± bifid tip, stiff, coriaceous, glabrous adaxially, midveins most prominent, marginal veins next largest, 2 other pairs of large veins conspicuous, transverse veinlets not evident. Inflorescences infrafoliar branched to 3 orders basally, to 1 order distally, branches stiffly spreading; peduncle short, stout, elliptical in cross-section; prophyll completely encircling peduncle at the base, tubular, 2-keeled, tapering distally, splitting abaxially, tomentose; peduncular bracts 2, longer than the prophyll, the first inserted just above the prophyll, the second an equal distance above the first, both tubular, complete, tapering to rather short pointed tips, glabrous, caducous; scars of 2–3 incomplete bracts above inner peduncular bract; rachis about twice as a long as the peduncle, rachis bracts low, each in a slit-like cavity, subtending primary branches; primary branches ca. 10, dorsiventrally flattened, with a short bare basal portion and 2 large lateral pulvini at the base, and distally bearing low bracts each in a slit-like cavity and subtending rachillae; rachillae angled, basally devoid of flowers, distally tapering and bearing spirally arranged low bracts subtending triads in the basal 1/3 and distally subtending paired or solitary staminate flowers, within the triads one staminate flower often distal and one lateral to the pistillate flower, rachillae ending in a short bare portion; first bracteole large, rounded, coriaceous, the second smaller and shallower. Staminate flowers very asymmetrical in bud, rounded or pointed apically; sepals 3, distinct, irregular, imbricate basally, keeled, prominently ridged when dry; petals 3, distinct, valvate, tips thickened, ridged when dry; stamens 6, filaments slender, inflexed at tip, anthers ± sagittate basally, slightly bifid apically, dorsifixed just below the middle, versatile, latrorse, connective tanniniferous; pistillode columnar, as long as the stamens. Pollen ellipsoidal asymmetric or oblate triangular, occasionally elongate; aperture a distal sulcus or trichotomosulcus; ectexine tectate, perforate and micro-channelled or finely perforate-rugulate, aperture margin similar or slightly finer; infratectum columellate; longest axis ranging from 48–58 µm [1/1]. Pistillate flower in young bud rounded; sepals 3, distinct, very broadly imbricate, extremely thick basally; petals 3, very broadly imbricate, thick basally, tips thick, valvate; staminodes joined in a ring with ca. 5 broad tooth-like tips; gynoecium irregularly obovoid, unilocular, uniovulate, stigmas 3, fleshy, ovule erect at stage studied, ?anatropous. Fruit large, obovoid to ellipsoid, somewhat asymmetrical, red at maturity single-seeded, with eccentrically apical, conical stigmatic remains; epicarp smooth, wrinkled basally at maturity, thin, mesocarp thick with close-packed longitudinal fibres, the innermost fibres adherent to the thick, whitish, bony, longitudinally ridged endocarp. Seed ± oblong-ovoid, flattened at the raphe, hilum impressed, ± subbasal, raphe branches numerous, radiating, diverging, many ascending, all anastomosing, endosperm homogeneous with a central hollow; embryo basal. Germination adjacent-ligular, eophyll bifid. Cytology: not studied. (J. Dransfield, N. Uhl, C. Asmussen, W.J. Baker, M. Harley and C. Lewis. 2008)

Relationships

  • Several studies place Carpoxylon as sister to a clade of Neoveitchia and Satakentia, all relationships with high support (Norup et al. 2006, Baker et al. in review, in prep.). However, moderate support has also been obtained for a sister relationship between Carpoxylon and Satakentia (Lewis andDoyle 2002, Asmussen et al. 2006). (J. Dransfield, N. Uhl, C. Asmussen, W.J. Baker, M. Harley and C. Lewis. 2008)

Bibliography

  • Dransfield, J. , Uhl, N. , Asmussen, C. , Baker, W.J. , Harley, M. & Lewis, C. 2008. Genera Palmarum. The evolution and classification of palms. Kew Publishing, Royal Botanic Gardens Kew.