Desmodium arizonicum |
Desmodium scopulorum |
|
---|---|---|
Arizona tick trefoil |
Sonoran ticktrefoil |
|
Habit | Herbs, perennial. | Herbs, annual. |
Stems | erect or ascending, usually striate, sparsely branched, 20–80 cm, pubescent. |
erect or ascending, usually striate, branched, 10–80 cm, pubescent. |
Leaves | trifoliolate; stipules caducous, narrowly ovate, 6–8 mm; petiole 1–5 mm; leaflet blades narrowly oblong-elliptic to linear, apex acute, surfaces villosulous; terminal blade 40–60 × 4–10 mm, length 3.5–10 times width. |
trifoliolate; stipules caducous, narrowly deltate to subulate, 3–4 mm; petiole 10–40 mm; leaflet blades narrowly ovate to ovate, apex acute to acuminate, surfaces densely uncinate-puberulent and pilose abaxially, uncinate-puberulent and pilose adaxially; terminal blade 20–100 × 7–25 mm, length 4–8 or 2–3 times width. |
Inflorescences | usually unbranched; rachis uncinate-puberulent; primary bracts caducous, broadly ovate, 4.5–5.5 mm. |
branched or unbranched; rachis uncinate-puberulent; primary bracts narrowly ovate, 1.4–2.6 mm. |
Pedicels | 8–15 mm. |
5–15 mm. |
Flowers | calyx 3 mm, uncinate-puberulent, lobes pubescent, tube 1.2 mm; abaxial lobes 2 mm, lateral lobes 1.5 mm; corolla blue-purple, 5–6 mm. |
calyx 1–1.5 mm, puberulent, tube 0.5 mm; abaxial lobes 1–1.5 mm, lateral lobes longer than tube; corolla pink, drying greenish yellow, 3–4 mm. |
Loments | sutures undulate abaxially, crenate adaxially; connections adaxial, 1/3 as broad as segments; segments (2 or)3–5, semiorbiculate, 4–5(–6) × 4 mm, rounded abaxially, convex adaxially, uncinate-puberulent; stipe 1–2 mm. |
sutures subequally incised, spirally arranged between young segments when young; connections adaxial, 1/8 as broad as segments; segments 2–4, proximal segments subrhombic, 4–6 × 2.5–3.5 mm, irregularly involute, uncinate-pubescent, distal segment semiorbiculate or broadly deltate, much larger than proximal segments, not contorted, 7–10 × 4–5 mm, glabrous, sutures uncinate-puberulent; stipe 1 mm. |
2n | = 22. |
|
Desmodium arizonicum |
Desmodium scopulorum |
|
Phenology | Flowering summer–fall. | Flowering fall. |
Habitat | Oak-juniper or pine woodlands, canyons, roadsides. | Open grassy slopes, oak-pine woodlands. |
Elevation | 1700–2500 m. (5600–8200 ft.) | 800–1800 m. (2600–5900 ft.) |
Distribution |
AZ; NM; Mexico (Baja California, Chihuahua, Sinaloa, Sonora, Tamaulipas)
|
AZ; Mexico (Baja California Sur, Sinaloa, Sonora) |
Discussion | In the flora area, Desmodium arizonicum is known from southeastern Arizona and adjacent New Mexico. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
In the flora area, Desmodium scopulorum is known from Pima and Santa Cruz counties. (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 | Meibomia arizonica | D. wigginsii, Meibomia scopulorum |
Name authority | S. Watson: Proc. Amer. Acad. Arts 20: 363. (1885) | S. Watson: Proc. Amer. Acad. Arts 24: 47. (1889) |
Web links |