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Pursh's milkvetch, woollypod milkvetch

curvepod milkvetch

Habit Plants perennial, acaulescent to shortly caulescent, densely villous to villous-tomentose, hairs basifixed. Plants perennial, caulescent, strigillose to villosulous or glabrate, hairs basifixed.
Stems

prostrate, loosely to densely tufted, 0–20 cm.

several–numerous, decumbent to ascending, 15–50 cm.

Leaves

1–12(17) cm;

leaflets (3)5–17(21), elliptic to oblanceolate, 2–14(20) × 1–7 mm;

tips obtuse to acute;

surfaces densely villous;

stipules 2.5–15 mm; free.

2.5–9 cm;

leaflets (9)11–21(25), obovate-cuneate, oblong-ovate or elliptic to broadly oblanceolate; (7)9–19(21) × 2–9 mm;

tips retuse or truncate to obtuse;

surfaces strigose to glabrescent or glabrous;

stipules 1–5 mm; free.

Inflorescences

racemes or subumbels, 1–12-flowered;

peduncles 1–14 cm;

bracts 4–9 mm;

pedicels 2–4.3 mm;

bracteoles 0–2.

racemes (5)10–25(35)-flowered;

peduncles 4–15 cm;

bracts 0.7–2.5 mm;

pedicels 1–3.5 mm;

bracteoles 0.

Flowers

ascending at anthesis;

calyces 5.5–16(19) mm, often purple, villous-pilose with white or mixed white and black hairs;

tubes 8.5–12.5 mm;

teeth subulate, 2.2–6 mm;

corollas 19–27 mm; whitish to ochroleucous or pink-purple;

ovules 14–40(46).

nodding at anthesis;

calyces gibbous-saccate or gibbous-truncate at bases, 6.1–13.6 mm, villosulous or strigose with white or black hairs or a mixture;

tubes 5.4–12 mm;

teeth triangular, 0.4–2.3 mm;

corollas 13.6–21 mm, white, ochroleucous, or lemon yellow;

ovules 14–25.

Fruits

unilocular, ascending, obliquely ovoid, usually curved, obcompressed, scarcely to deeply sulcate; (7)13–27(30) × 3.5–11 mm, densely white to tawny tomentose or densely villous;

hairs nearly always concealing valve surfaces;

valves coriaceous, sessile or on gynophores 0–1.6 mm.

unilocular, pendulous, narrowly oblong, crescentic, hamate, falcate or coiled through 1.5 spirals, strongly laterally compressed, bicarinate, 14–35 × 2.7–4.5 mm; cross reticulate, villosulous, strigillose, glabrate, or glabrous;

valves stiffly papery or thinly coriaceous;

stipes 6–20 mm.

Astragalus purshii

Astragalus curvicarpus

Distribution
[WildflowerSearch map]
[BONAP county map]
[WildflowerSearch map]
[BONAP county map]
Discussion

Western North America. ~8 varieties; 4 varieties treated in Flora.

Throughout western North America, particularly in the Intermountain Region, this is a low, tufted milkvetch with white or gray villous hairs and pods resembling balls of cotton. Barneby (1964) stated, “Attempts to devise a practical key to the varieties of A. purshii are never wholly successful.” Variety ophiogenes, the Snake River milkvetch, a native of Idaho, has been reported from Malheur County, but this is apparently based on misidentifications of A. purshii var. lagopinus. Variety ophiogenes has 3–11-flowered racemes and 9–17 leaflets.

3 varieties.

Source Flora of Oregon, volume 2, page 671
Richard Halse
Flora of Oregon, volume 2, page 662
Richard Halse
Sibling taxa
A. accidens, A. agrestis, A. alpinus, A. alvordensis, A. applegatei, A. arthuri, A. atratus, A. australis, A. beckwithii, A. californicus, A. calycosus, A. canadensis, A. caricinus, A. collinus, A. conjunctus, A. curvicarpus, A. cusickii, A. diaphanus, A. drummondii, A. eremiticus, A. filipes, A. gambellianus, A. geyeri, A. hoodianus, A. howellii, A. inflexus, A. iodanthus, A. kentrophyta, A. lemmonii, A. lentiginosus, A. malacus, A. misellus, A. mulfordiae, A. multiflorus, A. newberryi, A. nudisiliquus, A. obscurus, A. peckii, A. platytropis, A. reventus, A. robbinsii, A. salmonis, A. sclerocarpus, A. sheldonii, A. solitarius, A. spaldingii, A. sterilis, A. succumbens, A. tegetarioides, A. tetrapterus, A. toanus, A. tweedyi, A. tyghensis, A. umbraticus, A. vallaris, A. whitneyi
A. accidens, A. agrestis, A. alpinus, A. alvordensis, A. applegatei, A. arthuri, A. atratus, A. australis, A. beckwithii, A. californicus, A. calycosus, A. canadensis, A. caricinus, A. collinus, A. conjunctus, A. cusickii, A. diaphanus, A. drummondii, A. eremiticus, A. filipes, A. gambellianus, A. geyeri, A. hoodianus, A. howellii, A. inflexus, A. iodanthus, A. kentrophyta, A. lemmonii, A. lentiginosus, A. malacus, A. misellus, A. mulfordiae, A. multiflorus, A. newberryi, A. nudisiliquus, A. obscurus, A. peckii, A. platytropis, A. purshii, A. reventus, A. robbinsii, A. salmonis, A. sclerocarpus, A. sheldonii, A. solitarius, A. spaldingii, A. sterilis, A. succumbens, A. tegetarioides, A. tetrapterus, A. toanus, A. tweedyi, A. tyghensis, A. umbraticus, A. vallaris, A. whitneyi
Subordinate taxa
A. purshii var. glareosus, A. purshii var. lagopinus, A. purshii var. purshii, A. purshii var. tinctus
A. curvicarpus var. brachycodon, A. curvicarpus var. curvicarpus, A. curvicarpus var. subglaber
Synonyms Astragalus purshii var. ophiogenes
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