The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links
Photo is of parent taxon

Mancos milkvetch, Missouri milkvetch

Photo is of parent taxon

Missouri milk-vetch

Habit Plants subacaulescent to shortly caulescent. Plants usually shortly caulescent, sometimes subacaulescent.
Stems

to 10 cm.

to 15 cm.

Racemes

4–8-flowered.

(3–)5–15-flowered.

Flowers

calyx 8.5–13 mm, tube 7–10 mm, lobes 1.5–3 mm;

corolla usually pink-purple, rarely white;

banner (14.5–)16–22(–24) mm;

keel (11.5–)12.8–17.3(–18.5) mm.

calyx 9–12(–14.3) mm, tube 6.3–9(–9.3) mm, lobes 1.4–4.5(–5.3) mm;

corolla usually pink-purple, rarely white;

banner (14.5–)16–22(–24) mm;

keel (11.5–)12.8–17.3(–18.5) mm.

Legumes

sometimes deciduous, ascending to descending, dorsiventrally compressed, lunately incurved, ellipsoid, (11–)15–25 × 7–9 mm, unilocular, apex obcompressed proximal to incurved beak, strigose.

ascending, initially subterete or ± dorsiventrally compressed, ± straight, subsymmetrically oblong-ellipsoid, ± laterally compressed and obtuse-angled when mature, 15–28(–30) × (4–)5–9(–10) mm, subunilocular, base obtuse or sometimes cuneate, apex abruptly contracted into subulate, pungent beak, sutures prominent, strigulose.

Seeds

35–55.

(33–)40–50(–56).

2n

= 22.

Astragalus missouriensis var. amphibolus

Astragalus missouriensis var. missouriensis

Phenology Flowering May–Jul. Flowering late Mar–Jul.
Habitat Pinyon-juniper and sagebrush communities, on igneous or sandstone outcrops or sub­strates. Prairies, valleys, hillsides, dry open places, on limestone, shale, sandstone, or gyp­sum substrates.
Elevation 1600–2500 m. (5200–8200 ft.) 300–2400 m. (1000–7900 ft.)
Distribution
from FNA
AZ; CO; NM; UT
[BONAP county map]
from FNA
AZ; CO; IA; KS; MN; MT; ND; NE; NM; OK; SD; TX; WY; AB; MB; SK
[BONAP county map]
Discussion

The fruits of var. amphibolus are initially dorsiventrally compressed, and ultimately dehisce apically while still attached to the inflorescence (though sometimes deciduous). The fruits have a lateral ridge down each valve, with the valves separated by more or less prominent bicarinate keels. In these features, along with the typically persistent fruits, the plants can be distinguished from the similar Astragalus amphioxys var. amphioxys where their ranges are contiguous, as in northwestern New Mexico and vicinity. R. C. Barneby (1947b, 1964) suggested that hybridization occurs between the two taxa.

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

There is an irregular cline in flower size of var. missouriensis, from smallest in the north to largest in the south; caulescent forms appear to be more common southward (D. Isely 1998).

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

Source FNA vol. 11. FNA vol. 11.
Parent taxa Fabaceae > subfam. Faboideae > Astragalus > sect. Argophylli > Astragalus missouriensis Fabaceae > subfam. Faboideae > Astragalus > sect. Argophylli > Astragalus missouriensis
Sibling taxa
A. missouriensis var. humistratus, A. missouriensis var. mimetes, A. missouriensis var. missouriensis
A. missouriensis var. amphibolus, A. missouriensis var. humistratus, A. missouriensis var. mimetes
Name authority Barneby: Amer. Midl. Naturalist 37: 447. (1947) unknown
Web links