Desmanthus virgatus
Desmanthus brevipes
wild tantan
dwarf bundleflower
glabrous or sparsely pubescent with short white hairs along ribs, glabrescent.
glabrous or sparsely pubescent with short, white hairs along ribs, glabrescent.
1–3[–6.5] cm;
stipules persistent, 2.1–9 mm, with membranous, prominently veined auricle opposite petiole, glabrous or pubescent;
petiole 1–5 mm;
pinnae 2–5 pairs;
nectary present, sessile, crateriform, interpinnal between proximal pair of pinnae;
leaflets 22–46, blades 2.7–7 mm, venation obscure except for eccentric midvein, surfaces glabrous.
2.3–7.5 cm;
stipules persistent, 1.4–2.5 mm, with membranous auricles opposite petiole, glabrous;
petiole 3–7 mm;
pinnae 1 or 2 pairs;
nectary sessile, crateriform, between proximal pair of pinnae;
leaflets 38–52, blades 2.7–6.5 mm, venation obscure except for eccentric midvein, surfaces glabrous.
0.6–4 cm, 1–5.2 cm in fruit.
0–0.5 cm, 0.4–0.9 cm in fruit.
stamens 10;
staminodia 1.5–7.5 mm;
style not exserted beyond stamens.
stamens 10;
staminodia 1.5–2 mm;
style not exserted beyond stamens.
reddish brown to nearly black, straight or weakly falcate, linear, not constricted between seeds, dehiscent along both sutures, 2.2–6[–8.8] cm × 2.5–4 mm, apex acute to attenuate.
reddish brown to nearly black, ± falcate, linear, not constricted between seeds, dehiscent along both sutures, 3.5–5 cm × 3–3.5 mm, apex acute.
1 per axil, 3–22-flowered, sometimes only bisexual flowers present;
sterile flowers 0–8 per head; staminate and bisexual flowers 3–14 per head.
1 per axil, 7–9-flowered;
sterile flowers 1 or 2 per head; staminate and bisexual flowers 5–8 per head.
= 28.
= 28.
Desmanthus virgatus
Desmanthus brevipes
Desmanthus virgatus was the umbrella species in the genus for any taxon with inconspicuous flowers and unspecialized legumes; D. acuminatus, D. brevipes, and D. glandulosus have at times been considered varieties of this species, and D. leptophyllus and D. pernambucanus were synonymized with it in the tropics. The confusion is understandable because species differ in characteristics that may be difficult to see on a herbarium specimen, such as habit, degree of branching, taproot color and shape, and sleep movements of the leaves. Common garden studies (M. A. Luckow 1993) demonstrated that such characteristics are not phenotypic plasticity but have a genetic basis. In the flora area, D. virgatus is less variable than in Mexico, where one sees more erect forms with larger fruits and more flowers per inflorescence.
Desmanthus virgatus, as here circumscribed, is found throughout warmer areas in the New World; Old World species that have previously been considered D. virgatus are best referred to D. pernambucanus. Desmanthus virgatus has been intensively studied as a potential source of livestock feed for tropical areas.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Desmanthus brevipes is a segregate from the D. virgatus complex. The species was considered to be a variety of D. tatuhyensis by M. A. Luckow (1993), but subsequent study of the latter species in Argentina indicates that D. brevipes is distinct from its South American cousin. Desmanthus brevipes is easily distinguished by its sessile or very short flowering and fruiting peduncles.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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