Arecaceae

Desmoncus Mart.

First published in Hist. Nat. Palm. 2: 84 (1824)
This genus is accepted
The native range of this genus is Tropical America.

Descriptions

Vernacular
For common names, see Glassman 1972.
Distribution
Sixty-one species have been described but there are probably far fewer. Henderson et al. (1995) accept only seven species. Desmoncus is distributed from Mexico southwards to Brazil and Bolivia, and is absent from the West Indies except for Trinidad.
Morphology
Leaf (Tomlinson 1961), stem (Fisher and French 1976, Tomlinson and Zimmermann 2003), and root (Seubert 1998a, 1998b).
General Description
Slender, clustering (?always), spiny, pleonanthic, monoecious climbing palms. Stem covered with leaf sheaths, eventually becoming bare, with long internodes and conspicuous nodal scars, the first stem slender, not usually reaching a great height before being replaced by more robust sucker shoots (?always). Leaves pinnate, marcescent; sheath tubular, tightly sheathing, elongate, often tomentose and densely armed with spines in the distal exposed areas or glabrous and/or unarmed; ocrea well developed, armed or unarmed like the sheath, entire or disintegrating into a fibrous network; petiole very short to elongate, adaxially channelled, abaxially angled, usually with reflexed, bulbous-based spines; rachis elongate, usually curved, usually armed with swollen-based, reflexed spines, apically extended into a long cirrus armed with spines and pairs of small to robust, reflexed acanthophylls, acanthophylls absent on juvenile leaves, very rarely absent on adults; leaflets usually ovate, acuminate, often much narrowed at the base into a brief stalk, rather distant, ± regularly arranged or grouped, thin to coriaceous, with a conspicuous midrib and several more slender lateral veins, in Desmoncus cirrhiferus the main rib extended into a long flexuous tendril, margins smooth or armed with short spines, the main rib sometimes bearing spines, indumentum sometimes present in bands and along veins, transverse veinlets sometimes conspicuous. Inflorescences interfoliar, emerging through the leaf sheath mouths, branching to 1 order, becoming ± pendulous, apparently protandrous; peduncle elongate, slender, semicircular in cross-section; prophyll inserted some distance above the base of the peduncle, thinly coriaceous, 2-keeled, tubular, splitting longitudinally on the abaxial face and tattering, only partially exserted, persistent; peduncular bract 1, longer than and inserted far above the prophyll, thick, coriaceous to subwoody, tubular, enclosing the rachillae in bud, later splitting longitudinally, ± persistent, variously unarmed or spiny, adaxially smooth, often pale cream at anthesis, tomentose or ± glabrous abaxially; rachis shorter than the peduncle, bearing few to numerous, ± spirally arranged, flexuous, slender, short to elongate, often somewhat zig-zag rachillae, each subtended by a minute, triangular bract; rachillae very few to numerous, bearing rather distant, spiral, or subdistichous triads except in the distal ca. 1/3–1/5 where bearing paired or solitary staminate flowers, each flower group subtended by an inconspicuous triangular bract; bracteoles minute. Staminate flowers somewhat asymmetrical; calyx cupular, short, ± membranous with 3, low or acuminate, triangular lobes; petals 3, distinct, ± fleshy, ovate-lanceolate, much exceeding the calyx, acute or acuminate; stamens 6–9, filaments irregularly adnate to the petals, the free portion very short or moderate, very slender at the tip, anthers ± rectangular, basifixed, sagittate at the base, latrorse; pistillode minute, conical, or absent. Pollen ellipsoidal, usually with slight asymmetry; aperture a distal sulcus; ectexine tectate, finely perforate, perforate and micro-channelled, and rugulate, aperture margin may be slightly finer; infratectum columellate; longest axis 19–41 µm [5/12]. Pistillate flowers ± globular or ovoid, usually smaller than or equalling the staminate; calyx cupular or tubular, sometimes ± flattened, ± membranous, very briefly trilobed; corolla much exceeding the calyx, tubular, ± membranous, shallowly trilobed or truncate, sometimes minutely ciliate along the margins; staminodes 6, minute, tooth-like, epipetalous; gynoecium ovoid or columnar, trilocular, triovulate, only slightly exceeding the corolla, stigmas 3, fleshy, reflexed, ovule laterally attached, ?orthotropous. Fruit 1-seeded, ± ovoid or spherical, bright red, deep purple, or black, with apical stigmatic remains; epicarp smooth, mesocarp thin, fleshy, endocarp stony with 3 pores slightly distal to the equator. Seed ovoid, with 3 surface hollows, basally attached, hilum basal, circular, raphe branches densely anastomosing, endosperm homogeneous; embryo lateral. Germination adjacent-ligular; eophyll bifid with rather broad, acute segments or pinnate (2 pairs of leaflets in D. costaricensis). Cytology: 2n = 30. Distinguished from the other varieties by having leaves with 10-11 leaflets per side
Biology
Most species are palms of the lowlands, often found in open areas, swamps, on riverbanks, and more rarely in the undergrowth of tropical rain forest.
Diagnostic
Clustering spiny climbing palms of Central and South America, with reflexed acanthophylls borne on a whip at the end of the leaf.
[PW]

Uses

Use
Locally, Desmoncus species may provide cane for cordage or rarely for inexpensive furniture; they are not, however, utilised to the same extent as the Asiatic rattans. See also Hübschmann et al. 2007.
[PW]

Sources

  • Herbarium Catalogue Specimens

  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0

  • Kew Names and Taxonomic Backbone

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 International Plant Names Index and World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0

  • Palmweb - Palms of the World Online

    • Palmweb 2011. Palmweb: Palms of the World Online. Published on the internet http://www.palmweb.org. Accessed on 21/04/2013
    • Content licensed under Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License http://creativecommons.org/licenses/by-nc-sa/3.0