OregonFlora: Astragalus beckwithii vs. Astragalus tetrapterus

	Astragalus beckwithii	Astragalus tetrapterus
	Weiser's milkvetch	four-wing milkvetch
Habit		Plants perennial, caulescent, strigillose, hairs basifixed.
Stems		several, ascending to erect, becoming decumbent in fruit, 10–35(45) cm.
Leaves		1.5–9 cm; leaflets 9–23, linear, narrowly oblong or elliptic, 1–33 × 0.3–3.2 mm; tips obtuse to acute; surfaces glabrous to strigose; terminal leaflets confluent with rachis in the uppermost leaves; stipules 2–5.5 mm; free.
Inflorescences		racemes 6–15-flowered; peduncles 1–6.5 cm; bracts 1.5–3.5 mm; pedicels 1.4–4.3 mm; bracteoles 0–2.
Flowers		ascending at anthesis; calyces (4)5.5–8.7 mm, strigose with black or mixture of black and white hairs; tubes 3.5–7 mm; teeth subulate or triangular, 0.5–2.8 mm; corollas 15–19 mm, white to yellowish and pink or bright pink-purple-tinged; keel faintly to darkly purple-tipped; ovules 28–42.
Fruits		unilocular, declined or pendulous, obliquely oblong or clavate-oblong, curved or coiled, strongly carinate, obcompressed early, becoming sharply tetragonal and 4-winged; wings up to 2.5 mm wide at maturity; (16)20–40 × (4)6–10 mm, glabrous to strigose; valves stiffly papery to subcoriaceous; stipes 0.
2n		=22.

	Astragalus beckwithii	Astragalus tetrapterus
Distribution	[WildflowerSearch map] [BONAP county map]	[WildflowerSearch map] [BONAP county map]
Discussion		Hillsides of ash-clay-tuff, sandy soils, sagebrush. Flowering May–Jun. 900–1700 m. BR, ECas, Owy. ID, NV; southeast to AZ. Native. The four-winged fruits of this species are unique among Oregon milkvetches.
Source		Flora of Oregon, volume 2, page 675 Richard Halse
Sibling taxa	A. accidens, A. agrestis, A. alpinus, A. alvordensis, A. applegatei, A. arthuri, A. atratus, A. australis, 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. 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	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. purshii, A. reventus, A. robbinsii, A. salmonis, A. sclerocarpus, A. sheldonii, A. solitarius, A. spaldingii, A. sterilis, A. succumbens, A. tegetarioides, A. toanus, A. tweedyi, A. tyghensis, A. umbraticus, A. vallaris, A. whitneyi
Subordinate taxa	A. beckwithii var. weiserensis
Synonyms		Astragalus cinerascens, Astragalus tetrapterus var. cinerascens, Astragalus tetrapterus var. tetrapterus
Web links	Local floras: BC, OR, WA Local Web sites: Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: OR Local Web sites: Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Astragalus beckwithii

Astragalus tetrapterus

Weiser's milkvetch

four-wing milkvetch

Habit

Plants perennial, caulescent, strigillose, hairs basifixed.

Stems

several, ascending to erect, becoming decumbent in fruit, 10–35(45) cm.

Leaves

1.5–9 cm;

leaflets 9–23, linear, narrowly oblong or elliptic, 1–33 × 0.3–3.2 mm;

tips obtuse to acute;

surfaces glabrous to strigose;

terminal leaflets confluent with rachis in the uppermost leaves;

stipules 2–5.5 mm; free.

Inflorescences

racemes 6–15-flowered;

peduncles 1–6.5 cm;

bracts 1.5–3.5 mm;

pedicels 1.4–4.3 mm;

bracteoles 0–2.

Flowers

ascending at anthesis;

calyces (4)5.5–8.7 mm, strigose with black or mixture of black and white hairs;

tubes 3.5–7 mm;

teeth subulate or triangular, 0.5–2.8 mm;

corollas 15–19 mm, white to yellowish and pink or bright pink-purple-tinged;

keel faintly to darkly purple-tipped;

ovules 28–42.

Fruits

unilocular, declined or pendulous, obliquely oblong or clavate-oblong, curved or coiled, strongly carinate, obcompressed early, becoming sharply tetragonal and 4-winged;

wings up to 2.5 mm wide at maturity; (16)20–40 × (4)6–10 mm, glabrous to strigose;

valves stiffly papery to subcoriaceous;

stipes 0.

=22.