Geonoma Willd., Sp. Pl. 4: 593 (1805)

Primary tabs

http://media.e-taxonomy.eu/palmae/photos/palm_tc_89446_1.jpg

Discussion

Diagnosis

Biology And Ecology

Etymology

Uses

Description

  • Small to moderate, solitary or clustered, unarmed, pleonanthic, monoecious palms. Stem very short, subterranean, erect, or creeping, slender, sometimes tall, enclosed by thin leaf sheaths, becoming bare, usually cane-like, ringed with close or distant, conspicuous or inconspicuous leaf scars. Leaves pinnate, regularly or irregularly divided, or entire and bifid; sheath short, splitting opposite the petiole, margins fibrous, glabrous or variously tomentose; petiole short to long, slightly grooved or flattened adaxially, rounded abaxially, glabrous or tomentose; blade bifid, or with 2 or 3 pairs of leaflets, or irregularly divided, or nearly evenly pinnate, thin and papery or somewhat leathery, usually glabrous adaxially, glabrous, tomentose or with scales abaxially, especially along the main ribs, uniseriate hairs present or absent, midribs of single folds conspicuous, transverse veinlets not evident. Inflorescences solitary, interfoliar or infrafoliar, spicate, forked, or branched to 3(–4) orders, protandrous where known; peduncle very short to very long, glabrous or tomentose; prophyll tubular, short to long, pointed, very briefly 2-keeled laterally, membranous or leathery, glabrous or variously tomentose; peduncular bracts (0–)1(–2), short or long, deciduous or persistent, like the prophyll; rachillae straight or folded and twisted in bud, short to moderate, bearing rounded, truncate, or distally split, ± raised bracts, laterally adnate to the branch, decussate, spiral, or whorled and in definite rows, bracts closely appressed and the rachillae larger than the peduncle in diameter, or bracts more distant and the rachillae narrow, each bract subtending a triad of flowers sunken in a pit, pits without upper lip or upper lip distinct, glabrous or hairy, pit cavity glabrous or variously hairy; floral bracteoles 3, irregular, small, membranous. Staminate flowers about 1/2 exserted from the pit; sepals 3, distinct, chaffy, narrow, elongate, tips rounded, keeled or not; petals 3, connate for 2/3 their length, tips distinct, valvate; stamens (3) 6 (rarely more), filaments united with receptacle in a stalk-like base, connate in a tube above the base, free, narrow, flat, long or short distally, inflexed near the tip in bud, anthers borne at tips of the filaments, connective divided, thecae elongate, free and divaricate, or short and united, introrse; pistillode small, round, 3-lobed. Pollen ellipsoidal, usually with either slight or obvious asymmetry; aperture a distal sulcus; ectexine tectate, coarsely perforate or perforate and/or micro-channelled, and rugulate, aperture margin usually slightly finer; infratectum columellate; longest axis 22–48 µm [28/59]. Pistillate flowers sunken in the pit with only the tips of the floral organs exserted; sepals 3, united basally and adnate to the receptacle, often keeled, free and imbricate distally; petals 3, connate in a soft tube, briefly adnate to receptacle basally, ending in 3, valvate, chaffy, spreading lobes; staminodes united in a tube, truncate, 6-toothed or 6-lobed, lobes, if present, spreading at anthesis, tubes basally adnate to the receptacle, and sometimes also the corolla tube; gynoecium tricarpellate but 2 carpels vestigial at anthesis, unilocular, uniovulate, ovule anatropous, style tubular, lateral to basal, elongate, ending in 3 linear stigmas, recurved at anthesis. Fruit ±globose, sometimes somewhat pointed, green, brown, or purple-black, 1-seeded, stigmatic remains basal, the rachillae often becoming brightly coloured; epicarp, thin smooth, mesocarp thin, with narrow longitudinal fibres, endocarp thin, crustaceous to membranous. Seed ± globose, hilum short, basal, raphe encircling the seed, endosperm homogeneous; embryo erect basal. Germination adjacent-ligular; eophyll bifid. Cytology: 2n = 28. (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)

Anatomy

Fossil record

Relationships

Use Record

Uses

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