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Maryland tickclover, smooth small-leaf tick-trefoil

simple-leaf tick trefoil

Habit Herbs, perennial. Herbs, perennial.
Stems

ascending to erect, usually striate, branched or unbranched, 30–150 cm, glabrous or sparsely to densely uncinate-puberulent, sometimes also patent long-pilose.

ascending to erect, branched, 30–80 cm, inconspicuously uncinate-puberulent or glabrescent.

Leaves

trifoliolate;

stipules caducous or moderately persistent, subulate to narrowly ovate, 2–5 mm;

petiole 1–30 mm;

leaflet blades narrowly ovate, elliptic, elliptic-ovate, ovate-rhombic, or suborbiculate, apex obtuse or acute, mucronulate, surfaces sparsely to densely uncinate-puberulent and appressed-villous abaxially, uncinate-puberulent or glabrescent adaxially;

terminal blade 9–75 × 6–33 mm, length 1.5–4(–5) times width.

unifoliolate;

stipules ± persistent, narrowly ovate-deltate, 3–3.5 mm;

petiole 6–11 mm;

leaflet blades ovate to narrowly ovate, 30–80 × 10–30 mm, length (2–)2.5–5 times width, apex acute or obtuse, with paler patches along midrib adaxially, surfaces uncinate-puberulent and villous.

Inflorescences

terminal and branched, axillary and unbranched;

rachis uncinate-puberulent;

primary bracts ovate, 1.5–3 mm.

often numerous, slender and flexuous, branched or unbranched;

rachis densely uncinate-puberulent and villous;

primary bracts narrowly ovate, 1–2 mm.

Pedicels

3–19 mm, uncinate-puberulent.

4–10 mm.

Flowers

calyx 1.5–2.5 mm, pubescent (not uncinate-puberulent), tube 1 mm;

abaxial lobes 1.2–1.5 mm, lateral lobes 1 mm;

corolla usually lavender to red-violet or pink-purple, rarely white, 4–6 mm.

calyx 2.5–3 mm, puberulent and sparsely pilose, tube 1 mm;

abaxial lobes 2–3 mm, lateral lobes 2 mm, adaxial connate nearly to apex;

corolla pink to purple, 4–5 mm.

Loments

sutures crenate abaxially, sinuate adaxially;

connections adaxial, 1/4–1/2 as broad as segments;

segments 1–4, broadly elliptic, 3.5–5.5 × 2.5–4 mm, rounded abaxially, convex adaxially, uncinate-puberulent throughout;

stipe 1–2 mm.

margins slightly involute when young, sutures crenate abaxially, sinuate adaxially;

connections adaxial, 1/5 as broad as segments;

segments 3–5, elliptic to obovate, 2.5–6 × 3–3.5 mm, rounded abaxially, convex adaxially, sparsely uncinate-puberulent, sutures glabrous;

stipe 1.5–2.5 mm.

2n

= 22.

= 22.

Desmodium marilandicum

Desmodium psilophyllum

Phenology Flowering summer–fall.
Habitat Mountain woodlands, creek beds, terraces.
Elevation 1000–2200 m. (3300–7200 ft.)
Distribution
from USDA
e United States; sc United States; West Indies
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; TX; Mexico (Baja California Sur, Chiapas, Chihuahua, Coahuila, Durango, Hidalgo, Puebla, San Luis Potosí, Sinaloa, Sonora, Zacatecas)
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 3 (3 in the flora).

Desmodium ciliare, D. lancifolium, and D. marilandicum have generally been recognized as closely related but distinct species in floras of the United States. They commonly have two or three articulate, small loments. D. Isely (1990, 1998) grouped them as the D. ciliare Group and regarded forms intermediate between them as putative hybrids: D. ciliare × D. marilandicum and D. ciliare × D. lancifolium. They have been separated by differences in the leaflets and pubescence, but the differences are not always clear. They are treated here as one species with three varieties.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Desmodium psilophyllum is known in the flora area from southern Arizona to western and central Texas at the edge of Edwards Plateau; it is not known from New Mexico.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Terminal leaflet blades elliptic-ovate to narrowly ovate, 50–75 × 20–33 mm, apex acute to obtuse.
var. lancifolium
1. Terminal leaflet blades elliptic, ovate, ovate-rhombic, or suborbiculate, 9–40 × 6–17 mm, apex obtuse.
→ 2
2. Petioles 12–30 mm, sparsely uncinate-puberulent; stems with a few, scattered hairs; pedicels (6–)8–19 mm.
var. marilandicum
2. Petioles 1–15 mm; stems and petioles uncinate-puberulent and patent long-pilose; pedicels.
var. ciliare
Source FNA vol. 11. FNA vol. 11.
Parent taxa Fabaceae > subfam. Faboideae > Desmodium Fabaceae > subfam. Faboideae > Desmodium
Sibling taxa
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. 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. psilocarpum, 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
Subordinate taxa
D. marilandicum var. ciliare, D. marilandicum var. lancifolium, D. marilandicum var. marilandicum
Synonyms Hedysarum marilandicum, Meibomia marilandica Meibomia psilophylla
Name authority (Linnaeus) de Candolle in A. P. de Candolle and A. L. P. P. de Candolle: Prodr. 2: 328. (1825) — (as marylandicum) Schlechtendal: Linnaea 12: 310. (1838)
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