familyFabaceae
subfamilyFabaceae subfam. Faboideae
genusAstragalus
sectionAstragalus sect. Collini
speciesAstragalus collinus
Astragalus collinus var. laurentii
Amer. Midl. Naturalist 55: 487. 1956.
Common names: Lawrence’s milkvetch
EndemicConservation concern
Basionym: Homalobus laurentii Rydberg Bull. Torrey Bot. Club 51: 15. 1924
Synonyms: Astragalus laurentii (Rydberg) M. Peck
Treatment appears in FNA Volume 11.
Legumes gently incurved, obliquely ovoid-oblong, 8–15 × 3.3–4.2 mm, usually villosulous, rarely glabrous, hairs to 0.5–1 mm; stipe (3.5–)5–10 mm. Seeds (7 or)8–12.
Phenology: Flowering May–Jul.
Habitat: Dry grassy sites, on sandy or clay soils derived from basalt.
Elevation: 800–1100 m.
Discussion
In the southwestern corner of Morrow County and adjoining Gilliam County, Oregon, there are extensive and uniform populations of Astragalus collinus with glabrous fruits a little longer than the villosulous fruits of var. laurentii that may have resulted from introgression with A. curvicarpus var. subglaber. The indumentum of the herbage and impressed reticulation of the fruit are characteristic of A. collinus (R. C. Barneby 1964).
Selected References
None.
Lower Taxa
None.