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San Pedro tick trefoil

Santa Cruz Island ticktrefoil

Habit Herbs, perennial. Herbs or shrubs, perennial.
Stems

decumbent or decumbent-assurgent, branched, 30–120 cm, densely uncinate-pubescent.

erect or ascending, branched, 40–100 cm, slightly uncinate-pubescent and pilose or glabrescent.

Leaves

tri-foliolate;

stipules caducous, narrowly ovate, 5+ mm;

petiole 20–30 mm;

leaflet blades ovate-elliptic to narrowly so, apex acute to obtuse, surfaces densely appressed-pubescent abaxially, sparsely so adaxially;

terminal blade (20–)35–60 × 8–10(–15) mm, length 2.5–4 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

axillary and terminal, branched or unbranched;

rachis patent uncinate-puberulent to pubescent;

primary bracts closely imbricate before anthesis, caducous, ovate, 5 mm.

branched or unbranched;

rachis bulbous-villous and uncinate-puberulent;

primary bracts caducous, subulate, 1 mm.

Pedicels

5–10 mm.

10–20 mm, patent uncinate-pubescent.

Flowers

calyx 3–4 mm, sparsely pubescent, tube 1 mm;

abaxial lobes 3 mm, lateral lobes 2 mm;

corolla pink or purple to blue, 7–9 mm.

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 undulate abaxially, sinuate adaxially;

connections adaxial, 1/4–1/3 as broad as segments;

segments 4–7, semiorbiculate, 3–5 × 3–3.5 mm, rounded abaxially, slightly convex adaxially, glabrous or sparsely uncinate-puberulent throughout;

stipe 1–2 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.

Desmodium batocaulon

Desmodium psilocarpum

Phenology Flowering late summer–fall. Flowering late summer–fall.
Habitat Dry, rocky woodlands, pine or oak-juniper woodlands, canyons, roadsides. Woodland, grasslands, canyon slopes, streamsides.
Elevation 1200–2100 m. (3900–6900 ft.) 1000–2000 m. (3300–6600 ft.)
Distribution
from FNA
AZ; NM; Mexico (Baja California, Baja California Sur, Chihuahua, Guerrero, Sonora, Tamaulipas, Zacatecas)
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; NM; Mexico (Chihuahua, Nuevo León, Sonora, Tamaulipas)
[BONAP county map]
Discussion

In the flora area, Desmodium batocaulon is known from southeastern Arizona and southwestern New Mexico.

(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
D. arizonicum, D. canadense, D. canescens, D. cinerascens, D. cuspidatum, D. floridanum, D. grahamii, D. gramineum, D. illinoense, D. incanum, D. intortum, D. laevigatum, D. lindheimeri, D. lineatum, D. marilandicum, D. metcalfei, D. nuttallii, D. ochroleucum, D. paniculatum, D. procumbens, D. psilocarpum, D. psilophyllum, D. retinens, D. rosei, D. rotundifolium, D. scopulorum, D. scorpiurus, D. sessilifolium, D. strictum, D. tenuifolium, D. tortuosum, D. triflorum, D. tweedyi, D. viridiflorum, D. ×humifusum
D. arizonicum, D. batocaulon, D. canadense, D. canescens, D. cinerascens, D. cuspidatum, D. floridanum, D. grahamii, D. gramineum, D. illinoense, D. incanum, D. intortum, D. laevigatum, D. lindheimeri, D. lineatum, D. marilandicum, D. metcalfei, D. nuttallii, D. ochroleucum, D. paniculatum, D. procumbens, D. psilophyllum, D. retinens, D. rosei, D. rotundifolium, D. scopulorum, D. scorpiurus, D. sessilifolium, D. strictum, D. tenuifolium, D. tortuosum, D. triflorum, D. tweedyi, D. viridiflorum, D. ×humifusum
Synonyms Meibomia batocaulos Meibomia psilocarpa
Name authority A. Gray: Smithsonian Contr. Knowl. 5(6): 47. (1853) A. Gray: Smithsonian Contr. Knowl. 5(6): 48. (1853)
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