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creeping beggarweed, Spanish clover, Spanish tick-trefoil, zarzabacoa comun

Dixie tick trefoil

Habit Herbs, subshrubs, or shrubs, perennial; stoloniferous or rhizomatous. Herbs, perennial.
Stems

erect or ascending, to 300 cm, pubescent or glabrescent.

erect, 50–200 cm, medially uncinate-pubescent and patent-villous.

Leaves

trifoliolate;

stipules usually persistent, narrowly ovate-deltate, 5–10 mm;

petiole usually 15–20 mm;

leaflet blades elliptic to ovate, apex obtuse or acute, surfaces finely spreading-villosulous to substrigose abaxially, uncinate-puberulent or glabrescent adaxially;

terminal blade 20–90 × 15–45 mm, length 1.5–4 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

unbranched;

rachis densely patent uncinate-pubescent;

primary bracts caducous, narrowly ovate, 6–7 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

persistent with calyx-remnant at top after loments drop, 5–9 mm.

10–15 mm.

Flowers

calyx 2–3.5 mm, uncinate-puberulent, lobes pilose, tube 1 mm;

abaxial lobes 1.5–2.5 mm, lateral lobes 1–2 mm;

corolla purple, 5–8 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 symmetrically crenate abaxially, straight or slightly sinuate adaxially;

connections central, 1/2–2/3 as broad as segments;

segments 4–8, semiobovate, 3.5–5 × 2.5–3 mm, broadly rounded abaxially, straight or barely convex adaxially, uncinate-puberulent;

stipe 1.5–2 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.

= 22.

Desmodium incanum

Desmodium tortuosum

Phenology Flowering spring–fall. Flowering summer–fall (year-round).
Habitat Pine-palmetto flatwoods, woodland borders, lawns, ruderal sites, disturbed or waste areas. Open, dis­turbed sites, ruderal areas, pinelands, savannas.
Elevation 0–50 m. (0–200 ft.) 0–300 m. (0–1000 ft.)
Distribution
from FNA
AL; FL; GA; TX; Central America; South America; Mexico (Chiapas, Jalisco, Oaxaca, Quintana Roo, Tamaulipas, Veracruz); West Indies [Introduced in North America; introduced also in Asia (Taiwan), Africa, Indian Ocean Islands (Mauritius, Reunion), Pacific Islands, Australia]
[WildflowerSearch map]
[BONAP county map]
from FNA
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]
[WildflowerSearch map]
[BONAP county map]
Discussion

Desmodium incanum may be distinguished by its long-persistent stipules usually fused and nearly surrounding the stem, at least when young, and by its pedicels which are usually borne singly and are each subtended by one primary bract and two (lateral) secondary bracts (B. G. Schubert 1980).

Desmodium incanum was long known as D. canum Schinz & Thellung (= Meibomia cana S. F. Blake) based on the illegitimate Hedysarum canum J. F. Gmelin, a superfluous name for H. racemosum Aublet. The complex nomenclatural history was elaborated by D. H. Nicolson (1978) and L. C. P. Lima et al. (2012, 2014). Hedysarum canescens Miller (1768) is a later homonym of H. canescens Linnaeus (1753), thus illegitimate, and pertains here. Hedysarum canum J. F. Gmelin is a superfluous name for H. racemosum Aublet; Meibomia cana S. F. Blake was intended as a new combination based on that name.

(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 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. 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. psilocarpum, D. psilophyllum, D. retinens, D. rosei, D. rotundifolium, D. scopulorum, D. scorpiurus, D. sessilifolium, D. strictum, D. tenuifolium, D. triflorum, D. tweedyi, D. viridiflorum, D. ×humifusum
Synonyms Hedysarum incanum, Aeschynomene incana, D. ancistrocarpum, D. canum, D. frutescens, D. frutescens var. amplyophyllum, D. malacophyllum, D. mauritianum, D. supinum var. amblyophyllum, H. ancistrocarpum, H. malacophyllum, H. mauritianum, H. racemosum, Meibomia adscendens var. incana, M. incana, M. malacophylla, M. supina Hedysarum tortuosum, Meibomia purpurea, M. tortuosa
Name authority (Swartz) de Candolle in A. P. de Candolle and A. L. P. P. de Candolle: Prodr. 2: 332. (1825) — name conserved (Swartz) de Candolle in A. P. de Candolle and A. L. P. P. de Candolle: Prodr. 2: 332. (1825)
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