Desmoncus latisectus Burret, Repert. Spec. Nov. Regni Veg. 36: 215 (1934)

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Distribution

Map uses TDWG level 3 distributions (https://github.com/tdwg/wgsrpd)
Bolivia present (Henderson, A. 2011: A revision of Desmoncus (Arecaceae). – Phytotaxa 35: 1-88)A
From 9°48'-13°36'S and 61°33'-67°58'W in eastern Bolivia at 173(150- 200) m elevation in forest margins, forest patches in savannas, or near rocky river margins. (Henderson, A. 2011: A revision of Desmoncus (Arecaceae). – Phytotaxa 35: 1-88)A

Discussion

  • Taxonomic notes:-Only one specimen of Desmoncus latisectus has fruits (Moreno 19). These are scored as having uneven surfaces with numerous, subepidermal, short, often branching (Y-shaped) fibers, although these are obscure and not easily seen. Desmoncus latisectus is very similar to D. leptoclonos, and without fruits the two are difficult to distinguish. There are several quantitative differences between them (D. latisectus has narrower stems, shorter petioles, narrower rachises, fewer divisions, narrower basal pinnae), and their habitat also appears different. Desmoncus latisectus grows mostly at lower elevations in northeastern Bolivia in savanna-forest margins, whereas D. leptoclonos grows at higher elevations in gallery forest in the Cerrado in Brazil and Paraguay. (Henderson, A. 2011: A revision of Desmoncus (Arecaceae). – Phytotaxa 35: 1-88)A

Description

  • Plants 2.8(2.0-4.0) m tall; stems 0.9(0.5-1.4) cm diameter. Leaf petioles 2.0(1.0-3.0) cm long; rachises 34.1(29.0-40.0) cm long, 3.1(2.2-3.8) mm wide, the spines usually <1 cm long, mostly abaxial, recurved with markedly swollen bases; pinnae 6(5-8) per side of rachis, without long, filiform apices, without a beard of spines at the bases, without spinules or dense tomentum at the bases adaxially; basal pinna 11.2(7.9-14.5) cm long, 1.6(1.2-2.0) cm wide; cirri well-developed, with acanthophylls, with spines abaxially mostly on proximal part only, with no intermediate acanthophylls present, with a wide gap between pinnae and acanthophylls (i.e., gap wider than that between adjacent acanthophylls). Inflorescences with the rachis angular, slightly twisted, thicker than the few, closely spaced and spirally arranged rachillae, each rachilla not adnate to the rachis, subtended by an acute bracteole and with a well-developed axillary pulvinus; peduncles 2.4(1.1-3.2) mm wide; peduncular bracts 23.9(21.7-26.0) cm long, peduncular bracts broad, the surfaces ribbed or ridged, brown tomentose or glabrous, sparsely to moderately covered with short, straight or sinuous, briefly swollen-based, diagonally or vertically oriented spines, these flattened or triangular in cross-section, whitish-brown proximally, black or brown distally, with tomentose margins; rachillae 9(5-11), glabrous or scarcely tomentose initially; proximal rachillae 5.3(3.7-6.1) cm long, 0.8(0.7-1.0) mm wide; stamens no data; fruits 11.3 mm long, 9.0 mm wide, the surfaces uneven with numerous, subepidermal, short, often branching (Y-shaped) fibers; fruiting corollas less than one quarter as long as fruits, 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