Neonicholsonia Dammer, Gard. Chron. 1901(2): 178 (1901)

Primary tabs

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Number of Taxa

  • 1 species

Discussion

Biology And Ecology

Etymology

Diagnosis

Description

  • Small, acaulescent or short, solitary (?always), unarmed, pleonanthic, monoecious palm. Stem rhizomatous, or very short, sheathed by leaf bases. Leaves pinnate; sheaths short, thin, fibrous, opening opposite the petiole, not forming a crownshaft; petiole moderate, slender, 4-sided; Inflorescences solitary, interfoliar, spicate; peduncle very long, slender; rachis 4-sided basally, distally angled adaxially, rounded abaxially, prophyll short, 2-keeled laterally, splitting apically; peduncular bract glabrous; leaflets lanceolate or linear, rather short, tapering to a point, much longer than the prophyll, terete, slender, beaked, splitting opposite to subopposite, single-fold, distal pair sometimes united basally, abaxially; flower-bearing portion also elongate but shorter than the thin and papery, adaxially glabrous, abaxially lightly waxy-tomentose, peduncle, densely hairy becoming glabrous, bearing spirally arranged, midrib prominent, transverse veinlets not evident or visible and short. closely crowded, shallow, pointed bracts each subtending a triad basally and pairs of or single staminate flowers distally; floral bracteoles conspicuous, shallow, pointed, the outer markedly larger than the inner. Staminate flowers lateral to the pistillate, somewhat variable, ovoid, curved in bud; sepals 3, basally connate for 1/2 their length in a short erect cupule with 3 long, narrow, pointed tips, keeled or not; petals 3, distinct, valvate, about twice as long as the sepals, striate, grooved adaxially, narrow or rather broad, tips thickened; stamens 6, distinct or briefly connate basally, filaments awl-shaped, somewhat enlarged basally, antesepalous filaments shorter, anthers elongate, medifixed, basally ± sagittate, versatile, latrorse, connective ± prolonged in a tip; pistillode short or slender and elongate, trifid apically or throughout. Pollen ellipsoidal, with slight or obvious asymmetry; aperture a distal sulcus; ectexine semitectate, coarsely foveolate-reticulate or reticulate, aperture margin slightly coarsely perforate or foveolate; infratectum columellate; longest axis 55–62 µm [1/1]. Pistillate flowers ovoid; sepals 3, distinct, partially imbricate, margins somewhat fringed, tips pointed, striate; petals like the sepals but tips thickened, valvate; staminodes lacking; gynoecium ovoid, unilocular, uniovulate, style not evident, stigma with 3 fleshy lobes, briefly reflexed, papillose adaxially, ovule basally attached, form unknown. Fruit ovoid, black when mature, irregular, remnants of 2 abortive carpels present, stigmatic remains apical to subapical forming a distinct beak; epicarp thin, smooth, mesocarp thin, composed of large, flat fibres, endocarp thin, crustaceous. Seed globose, hilum basal, raphe branches few, large, deeply sunken making the endosperm ruminate peripherally; embryo large, basal to subbasal. Germination adjacent ligular; eophyll bifid, the tips further divided. Cytology: 2n = 36. (J. Dransfield, N. Uhl, C. Asmussen, W.J. Baker, M. Harley and C. Lewis. 2008)

Anatomy

Relationships

Taxonomic accounts

Fossil record

  • From the Upper Oligocene–Lower Mocene of Mexico (State of Chiapas), a single flower has been found that, “has some features found in the genus Neonicholsonia, but cannot be placed with certainty in any extant genera” (Poinar 2002a). Two monosulcate palm pollen types are recovered from the Pliocene, Gatun Lake Formation, Panama (Graham 1991). The second of these types, bisymmetrical and finely reticulate, is compared with Colpothrinax, Cryosophila and Neonicholsonia. Of these, Cryosophila is the most probable identity. (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.