Desmodium retinens |
Desmodium tortuosum |
|
---|---|---|
Santa Rita Mountain ticktrefoil |
Dixie tick trefoil |
|
Habit | Herbs, perennial, diffuse; base woody, rootstock woody. | Herbs, perennial. |
Stems | erect, ascending, or procumbent, usually striate, 30–60(–100) cm, sparsely to densely pilose and uncinate-pubescent. |
erect, 50–200 cm, medially uncinate-pubescent and patent-villous. |
Leaves | trifoliolate, sometimes unifoliolate proximally; stipules persistent, recurved, subulate, 2–3 mm; petiole 7–25 mm; leaflet blades usually oblong-ovate to narrowly so, sometimes broadly elliptic to oblong, apex obtuse or acute, surfaces sparsely uncinate-puberulent; terminal blade 10–30(–35) × 8–10 mm, length 1–3.5 times width. |
trifoliolate; stipules persistent, often patent or reflexed, obliquely ovate and apex acuminate or narrowly ovate and apex aristate, 3–12.5 mm, base amplexicaul; petiole 8–50 mm; leaflet blades narrowly ovate to ovate, elliptic, or rhombic, apex obtuse or acute, surfaces obscurely prominently reticulate-veined abaxially, uncinate-puberulent and strigose or subappressed-villous; terminal blade (20–)40–150 × 10–50 mm, length 2–3 times width. |
Inflorescences | usually unbranched, sometimes branched; rachis patent uncinate-puberulent; primary bracts narrowly ovate, 2.5–3 mm. |
branched or unbranched; rachis villous (often with bulbous hairs) and uncinate-puberulent, or only uncinate-puberulent; primary bracts caducous, narrowly ovate, 4 mm. |
Pedicels | 8–15 mm. |
10–15 mm. |
Flowers | calyx 1.5–2.5 mm, pubescent, tube 1 mm; abaxial lobes 1.5 mm, lateral lobes 1 mm; corolla pink-purple, 4–5 mm. |
calyx 1.5–3 mm, uncinate-puberulent, tube to 1 mm; abaxial lobes 2 mm, lateral lobes 1 mm; corolla lavender, 4–6 mm. |
Loments | sutures subequally crenate; connections central, 1/5–1/4 as broad as segments; segments 2–7, rounded or broadly elliptic, 2.5–3 × 2.5 mm, abaxially and adaxially rounded, glabrous or slightly puberulent; stipe 1–2 mm. |
margins alternately involute and revolute, sutures equally crenate, twisted conspicuously when young; connections central, 1/4 as broad as segments; segments (3 or)4–7, orbiculate, broadly elliptic, or rhombic, 3–4.5 × 3–3.5 mm, rounded abaxially and adaxially, densely uncinate-pubescent; stipe 0.5–1 mm. |
2n | = 22. |
|
Desmodium retinens |
Desmodium tortuosum |
|
Phenology | Flowering late summer–fall. | Flowering summer–fall (year-round). |
Habitat | Wooded or grassy rocky slopes, oak or oak-pine forests. | Open, disturbed sites, ruderal areas, pinelands, savannas. |
Elevation | 1400–2100 m. (4600–6900 ft.) | 0–300 m. (0–1000 ft.) |
Distribution |
AZ; Mexico; Central America (Guatemala) |
AL; AR; FL; GA; LA; MS; NC; SC; TX; Central America; South America; Mexico (Chiapas, Colima, Guerrero, Jalisco, Nayarit, Oaxaca, Sinaloa, Sonora); West Indies [Introduced in North America; introduced also in Asia, Africa, Indian Ocean Islands, Pacific Islands, Australia]
|
Discussion | Desmodium retinens is known in the flora area from Cochise, Graham, Pima, and Santa Cruz counties. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Desmodium tortuosum is most easily distinguished from its relatives by the thick leaflets with prominent reticulate venation, the large persistent stipules, and the long, stiff, ascending to spreading pedicels (B. G. Schubert 1980). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 11. | FNA vol. 11. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | D. wislizeni, Meibomia retinens | Hedysarum tortuosum, Meibomia purpurea, M. tortuosa |
Name authority | Schlechtendal: Linnaea 12: 311. (1838) | (Swartz) de Candolle in A. P. de Candolle and A. L. P. P. de Candolle: Prodr. 2: 332. (1825) |
Web links |