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with a well-developed axillary pulvinus; peduncles 4.3(2.8–5.7) mm wide; peduncular bracts length no data,
broad, the surfaces ribbed, brown tomentose, sparsely to densely covered with long, 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 (rarely without spines); rachillae
21(20–21), glabrous or scarcely tomentose initially; proximal rachillae 8.5 cm long, 1.0 mm wide; stamens no
data; fruits 15.8(14.0–17.9) mm long, 14.2(12.8–16.3) mm wide, the surfaces uneven with numerous,
subepidermal, long, branching fibers; fruiting corollas less than one quarter as long as fruits, splitting
irregularly into 3 lobes, the lobes often splitting again; endocarps broadly obovoid with flattened apices, the
pores lateral on or near flattened apices.
Distribution and habitat:—From 8°40’–9°30’N and 77°25’–80°29’W in central Panama, with outliers
to the west and east, at 173(25–400) m elevation in lowland rainforest (Fig. 10).
FIGURE 10. Distribution maps of Desmoncus myriacanthos, D. obovoideus, D. osensis, D. orthacanthos, and D.
parvulus.
Taxonomic notes:—Desmoncus obovoideus is similar to D. osensis and shares all character states except
that D. obovoideus lacks data for stamen number. Desmoncus obovoideus also has shorter and wider basal
pinna compared to D. osensis (mean of 14.0 cm long and 4.9 cm wide versus 23.2 cm long and 3.7 cm wide).
Based on this, and geographic separation, the two are recognized as separate species.
A few specimens have abaxial rachis spines which appear almost recurved, more like those of D.
polyacanthos. There are two outliers, both of which are tentatively included here. The one from eastern
A REVISION OF DESMONCUS (ARECACEAE)
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