Ponapea Becc., Bot. Jahrb. Syst. 59: 13 (1924)

Primary tabs

http://media.e-taxonomy.eu/palmae/photos/palm_tc_163213_2.jpg

Number of Taxa

  • 4 species

Discussion

Biology And Ecology

Etymology

Diagnosis

Description

  • Moderate, solitary, unarmed, pleonanthic, monoecious palm. Stem erect, moderate, smooth, grey, ringed with leaf scars. Leaves pinnate, arching; sheath forming a prominent crownshaft, abaxially densely covered with grey scales; petiole well developed, deeply channelled adaxially, rounded abaxially, covered with small brown punctiform scales; rachis channelled basally, ridged distally; leaflets broadly lanceolate, regularly arranged, tips oblique to truncate, conspicuously praemorse, adaxially glabrous, abaxially covered with numerous dark brown ramenta on major veins, transverse veinlets not apparent. Inflorescences infrafoliar, held horizontally, branched to 4 orders basally, to 2–1 orders distally; peduncle short, rather slender, flattened, glabrous; prophyll tubular, membranous, bearing scattered scales, rounded at the tip, splitting abaxially allowing the peduncular bract to emerge; peduncular bract borne just above the prophyll, exceeding the prophyll, longitudinally splitting, caducous, bearing scales as the prophyll; peduncular bract tubular, caducous, shortly beaked, splitting abaxially, adaxially glabrous, abaxially densely to lightly covered in stellate brown scales, scar of 1 incomplete peduncular bract present; rachis much longer than the peduncle, elongate, tapering, bearing rather widely spaced ± angled first-order branches, each subtended by a very small, ridge-like bract; rachillae white, slender, spreading, somewhat divaricate and zig-zag, glabrous, bearing subdistichous, distant triads of flowers for 2/3 their length and paired to solitary staminate flowers distally; floral bracteoles large, low, rounded. Staminate flowers symmetrical, bullet-shaped; sepals 3, distinct, broadly imbricate, irregularly rounded, somewhat gibbous; petals 3, distinct, ovate, valvate, evenly thickened, adaxially grooved; stamens ca. 100, filaments erect in bud, short, awl-shaped, anthers oblong-elliptical, curled, deeply bifid basally and apically, dorsifixed near the base, ?latrorse, connective broad, tanniniferous; pistillode conical, much shorter than the stamens. Pollen ellipsoidal asymmetric; aperture a distal sulcus; ectexine tectate, finely perforate-rugulate, aperture margin similar or slightly finer; infratectum columellate; longest axis 43–51 µm [1/3]. Pistillate flowers ovoid; sepals 3, distinct, imbricate, rounded, margins variously split; petals 3, distinct, broadly ovate and imbricate, tips thick, valvate, opening briefly apically to expose the stigmas at anthesis; staminodes 3, irregular, tooth-like; gynoecium asymmetrical, ovoid with a bulge on one side, unilocular, uniovulate, stigmas 3, fleshy, recurved at anthesis, ovule very large, laterally attached, form unknown. Fruit ovoid when fresh, drying irregularly 5-ridged, red at maturity, stigmatic remains apical, perianth persistent; epicarp smooth, becoming somewhat striate when dry, mesocarp fleshy, endocarp thick, black, conspicuously 5-ridged (Ponapea leddermanniana), ridged and straw-coloured (P. hosinoi), or terete and straw-coloured (P. palauensis). Seed attached laterally, ovoid, conforming to the shape of the endocarp, hilum elongate, raphe branches anastomosing, endosperm homogeneous; embryo basal. Germination adjacent-ligular; eophyll bifid with broad conspicuously praemorse lobes. Cytology not studied. (J. Dransfield, N. Uhl, C. Asmussen, W.J. Baker, M. Harley and C. Lewis. 2008)

Relationships

  • Ponapea is a strongly supported monophyletic group that is resolved as sister to Drymophloeus hentyi with high support (Lewis et al. in prep.). Asmussen et al. (2006), Norup et al. (2006) and Baker et al. (in review) resolve Ponapea as sister to Ptychosperma with low to moderate support, but D. hentyi was not sampled in these studies. (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.