Desmoncus setosus Mart., Hist. Nat. Palm. 2: 89 (1824)

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Distribution

Map uses TDWG level 3 distributions (https://github.com/tdwg/wgsrpd)
Brazil North present (Henderson, A. 2011: A revision of Desmoncus (Arecaceae). – Phytotaxa 35: 1-88)A
Colombia present (Henderson, A. 2011: A revision of Desmoncus (Arecaceae). – Phytotaxa 35: 1-88)A
From 1°51'-3°45'S and 59°58'-69°50'W in the central Amazon region of Brazil (Amazonas) and Colombia (Amazonas) at low elevations in várzea forest or disturbed forest near rivers. (Henderson, A. 2011: A revision of Desmoncus (Arecaceae). – Phytotaxa 35: 1-88)A

Discussion

  • Taxonomic notes:-Specimens included here were placed by Henderson (1995) in Desmoncus polyacanthos. They differ from that species in their uneven fruit surfaces with numerous, subepidermal, short, often branching (Y-shaped) fibers. However, they are a heterogeneous group of specimens and there seems a possibility that there is more than one taxon here (or hybrids), but many more specimens are needed to decide the matter. An epitype is designated because the type is sterile.
    Subspecific variation:-One specimen (Coêlho 2078), tentatively included here, from Ilha do Marapata has inflorescences with the rachilla bracteoles displaced distally onto the rachilla, similar to those of D. orthacanthos. Several specimens have pinnae bases with small spines but these appear different from the pinnae bases of some other taxa (pinnae bases with uneven surfaces at the bases adaxially, usually covered with spinules and/or dense tomentum). (Henderson, A. 2011: A revision of Desmoncus (Arecaceae). – Phytotaxa 35: 1-88)A

Description

  • Plants 7.0(2.0-15.0) m tall; stems 0.7(0.5-1.1) cm diameter. Leaf petioles 2.0(1.0-4.0) cm long; rachise 41.7(14.0-67.0) cm long, 2.9(2.2-4.1) mm wide, the spines usually <1 cm long, mostly abaxial, recurved wit markedly swollen bases; pinnae 8(6-11) per side of rachis, without a beard of spines at the bases, without spinules or dense tomentum at the bases adaxially; basal pinna 12.7(5.5-19.5) cm long, 0.7(0.3-1.3) cm wide cirri well-developed, with acanthophylls, acanthophylls present, with few spines abaxially, mostly o proximal part only, with no intermediate acanthophylls present, usually with a wide gap between pinnae an acanthophylls (i.e., gap wider than that between adjacent acanthophylls). Inflorescences with the rachi angular, slightly twisted, thicker than the few to numerous, closely spaced and spirally arranged rachillae, each rachilla not (or very rarely) adnate to the rachis, subtended by an acute bracteole and with a welldeveloped axillary pulvinus; peduncles 1.5(0.9-1.9) mm wide; peduncular bracts 19.1(14.5-23.0) cm long, broad, the surfaces ridged, brown tomentose, sparsely to densely covered with short, recurved, markedly swollen-based, diagonally oriented spines, these triangular in cross-section, whitish-brown proximally, brown distally, with tomentose margins; rachillae 9(4-15), glabrous or scarcely tomentose initially; proximal rachillae 5.3(2.8-7.0) cm long, 0.9(0.5-1.7) mm wide; stamens no data; fruits 11.9(11.2-12.8) mm long, 7.5(6.1-8.5) mm wide, the surfaces uneven with numerous, subepidermal, short, often branching (Y-shaped) fibers; fruiting corollas splitting irregularly into 3 lobes, the lobes often splitting again; endocarps globose to obovoid with rounded or slightly peaked apices, the pores lateral. (Henderson, A. 2011: A revision of Desmoncus (Arecaceae). – Phytotaxa 35: 1-88)A

Bibliography

    A. Henderson, A. 2011: A revision of Desmoncus (Arecaceae). – Phytotaxa 35: 1-88