Desmodium triflorum |
Desmodium psilocarpum |
|
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creeping tick trefoil, matty desmodium, three-flower beggarweed, threeflower ticktrefoil, tropical trefoil |
Santa Cruz Island ticktrefoil |
|
Habit | Herbs, annual or perennial, often mat-forming; stoloniferous. | Herbs or shrubs, perennial. |
Stems | prostrate, densely branched, 20–80 cm, ascending-pilose or strigose. |
erect or ascending, branched, 40–100 cm, slightly uncinate-pubescent and pilose or glabrescent. |
Leaves | trifoliolate; stipules persistent, narrowly ovate, 3–5 mm; petiole 3–7.5 mm; leaflet blades broadly obovate or cuneate-obovate, often folding downwards, apex emarginate, surfaces usually sparsely uncinate-puberulent or subappressed-pilose along midrib abaxially, rarely entire surface, glabrous adaxially; terminal blade 5–10 × 3–11 mm, length 0.8–1.2 times width. |
trifoliolate; stipules mostly persistent, broadly ovate, 4–10 mm, base subamplexicaul; petiole 30–40 mm; leaflet blades broadly ovate-elliptic or ovate to narrowly ovate, apex acute, surfaces uncinate-puberulent; terminal blade 20–70(–100) × 10–20(–50) mm, length 1.8–2 times width. |
Inflorescences | terminal fascicles opposite distal leaf, appearing axillary, unbranched; rachis pubescent; primary bracts narrowly ovate, 4 mm. |
branched or unbranched; rachis bulbous-villous and uncinate-puberulent; primary bracts caducous, subulate, 1 mm. |
Pedicels | 8–12 mm. |
10–20 mm, patent uncinate-pubescent. |
Flowers | calyx 2.5–3 mm, appressed-pubescent, tube 1.2 mm; abaxial lobes 1.5–1.7 mm, lateral lobes 1.5–1.7 mm, adaxial lobes deeply 2-toothed; corolla pale pink to purplish, 4–5 mm, keel distinctly longer than wings. |
calyx 1.5–2 mm, pilose and uncinate-puberulent, tube 0.8 mm; abaxial lobes 1 mm, lateral lobes 0.8–1 mm; corolla pink-purple, fading greenish, 4–5 mm. |
Loments | sutures weakly crenate abaxially, with broad connection between segments, barely sinuate adaxially; connections 2/3–4/5 as broad as segments; segments 3–5, nearly square, 2.5–3.5 × 2.5–3 mm, symmetrically convex abaxially, slightly concave adaxially, inconspicuously uncinate-pubescent or glabrescent; stipe 0 mm. |
sutures subequally deeply crenate; connections central, 1/8–1/7 as broad as segments; segments 3–6, rounded, 6–10 × 5–7 mm, rounded, sparsely pubescent, at least on sutures; stipe 1(–2) mm. |
2n | = 22. |
|
Desmodium triflorum |
Desmodium psilocarpum |
|
Phenology | Flowering year-round. | Flowering late summer–fall. |
Habitat | Ruderal areas, lawns, disturbed open woodlands. | Woodland, grasslands, canyon slopes, streamsides. |
Elevation | 0–50 m. (0–200 ft.) | 1000–2000 m. (3300–6600 ft.) |
Distribution |
FL; LA; Central America; South America; Mexico (Jalisco, Sinaloa); West Indies; Asia; Africa [Introduced in North America; introduced also in Indian Ocean Islands, Pacific Islands, Australia]
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AZ; NM; Mexico (Chihuahua, Nuevo León, Sonora, Tamaulipas) |
Discussion | Inflorescences of Desmodium triflorum are produced opposite the leaf at the distal end of stem and are usually described as axillary. The branching system of D. triflorum is a monopodial sympodium and the inflorescences are terminal (H. Ohashi and T. Nemoto 1986). Evolution of inflorescences in Desmodium is inferred from comparative morphology and anatomy with Campylotropis, Kummerowia, and Lespedeza (Nemoto and Ohashi 1990, 1993, 1996). Based on molecular and morphological data, H. Ohashi and K. Ohashi (2018) transferred Desmodium triflorum and the other species formerly in Desmodium sects. Nicolsonia (de Candolle) Bentham and Sagotia (Duchassaing & Walpers) Bentham to the genus Grona Loureiro. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Desmodium psilocarpum is known in the flora area from southern Arizona and adjacent southwestern New Mexico. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 11. | FNA vol. 11. |
Parent taxa | Fabaceae > subfam. Faboideae > Desmodium | Fabaceae > subfam. Faboideae > Desmodium |
Sibling taxa | ||
Synonyms | Hedysarum triflorum, Grona triflora, Meibomia triflora, Sagotia triflora | Meibomia psilocarpa |
Name authority | (Linnaeus) de Candolle in A. P. de Candolle and A. L. P. P. de Candolle: Prodr. 2: 334. (1825) | A. Gray: Smithsonian Contr. Knowl. 5(6): 48. (1853) |
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