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spike ticktrefoil

Canada tickclover, Canadian tick-trefoil, showy tick-trefoil

Habit Herbs, perennial; base woody. Herbs, perennial.
Stems

ascending to erect or sprawling, usually striate, branched, 60–150 cm, sparsely to densely appressed-pilose and sparsely uncinate-pubescent.

erect, 50–100 cm, sparsely to densely pilose or villous, usually patent uncinate-puberulent and -pubescent, sometimes glabrescent.

Leaves

trifoliolate;

stipules caducous, narrowly ovate-deltate, 3–4 mm;

petioles 20–40 mm proximally, 8–20 mm distally;

leaflet blades narrowly elliptic-oblong, apex obtuse, lateral veins prominent, reaching margin, margin flat, surfaces subappressed-villous abaxially, glabrescent adaxially;

terminal blade 25–70 × 15–25 mm, length 2–3 times width.

trifoliolate;

stipules ± persistent, subulate to narrowly ovate, 4.5–9.5 mm;

petiole 10–60 mm;

leaflet blades often pale green abaxially, ovate to narrowly ovate, apex acute, surfaces slightly or visibly strigulose abaxially, sparsely puberulent or nearly glabrescent adaxially;

terminal blade 40–110 × 15–30 mm, length 2.5–3.5 times width.

Inflorescences

branched or unbranched and elongate when terminal, or unbranched from distal axils;

rachis closely appressed-pubescent and patent uncinate-puberulent;

primary bracts caducous, narrowly ovate, 3–5 mm.

terminal and branched, or unbranched from distal axils;

rachis villous and uncinate-pubescent, sometimes appearing glabrescent;

primary bracts caducous, narrowly ovate, 6–7 mm.

Pedicels

8–10 mm.

4–8 mm.

Flowers

calyx 4 mm, densely uncinate-puberulent, tube 2 mm;

abaxial lobes 2 mm, lateral lobes 1 mm;

corolla purple, 8–11 mm.

calyx 3.5–5 mm, densely uncinate-puberulent and sparsely pilose, tube 1–1.5 mm;

abaxial lobes 3–3.5 mm, lateral lobes 2 mm;

corolla usually blue-violet, rarely white, 8–11 mm.

Loments

sutures crenate;

connections central, 1/3 as broad as segments;

segments 3–8, semiorbiculate, 5–7 × 4–5 mm, rounded abaxially, convex adaxially, villosulous or pubescent and uncinate-puberulent throughout;

stipe 2–5 mm.

sutures crenate abaxially, repand or sinuate adaxially;

connections adaxial, 1/2 as broad as segments;

segments 3–5, semiorbiculate, 4–8 × 4–5 mm, rounded abaxially, convex adaxially, densely uncinate-puberulent;

stipe 2(–3) mm.

2n

= 22.

Desmodium cinerascens

Desmodium canadense

Phenology Flowering late summer–fall. Flowering summer.
Habitat Open, dry slopes, with oak or pine, canyons, washes, roadsides. Prairie relics, woodland borders and openings, roadsides.
Elevation 1200–1800 m. (3900–5900 ft.) 0–900 m. (0–3000 ft.)
Distribution
from FNA
AZ; Mexico (Chihuahua, Durango, Nayarit, Sinaloa, Sonora)
[BONAP county map]
from FNA
CT; DE; IA; IL; IN; KS; MA; MD; ME; MI; MN; MO; ND; NH; NJ; NY; OH; OK; PA; RI; SD; TX; VA; VT; WI; WV; MB; NB; NS; ON; QC
[WildflowerSearch map]
[BONAP county map]
Discussion

Desmodium cinerascens is known in the flora area from the south-central and southeastern areas of Arizona.

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

In Texas, Desmodium canadense is known only from Wheeler County.

(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. 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. 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
Synonyms Meibomia cinerascens Hedysarum canadense, Meibomia canadensis
Name authority A. Gray: Smithsonian Contr. Knowl. 5(6): 48. (1853) (Linnaeus) de Candolle in A. P. de Candolle and A. L. P. P. de Candolle: Prodr. 2: 328. (1825)
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