Astragalus racemosus Pursh 

 RACEME MILKVETCH 

 Bean Family (Fabaceae) 



CONSERVATION STATUS 



U.S. Fish and Wildlife Service: None. 



Bureau of Land Management: Watch 



Montana Natural Heritage Program: G5 SI; the species as a whole is demonstrably secure 

 globally, but may be critically imperiled in Montana where it is extremely rare. Note: This 

 study provides a basis for changing the state rank. 



DESCRIPTION: Raceme milkvetch is a coarse, herbaceous perennial with few to many erect 

 stems, 15-70 cm (6-28 in) high, from a woody taproot and branched rootcrown. The pinnately 

 compound leaves are 4-15 cm (2-6 in) long with 11-31 narrowly to broadly elliptic leaflets. The 

 foliage is thinly to densely covered with short basally attached hairs. Inflorescences with 15-70 

 densely clustered flowers arise from the axils of the upper leaves. Nodding, whitish flowers are 16- 

 21mm (ca. 0.5 in) long with a partially reflexed upper petal and purplish tinged lower petals. 

 Astragalus bisulcatus seen in Carter County during this study had purplish flowers, but color is 

 variable for the species. The calyx is 8-1 1 mm long and glabrous (lacking hairs) or with scattered 

 hairs. The pendent, oblong-elliptic pods have a basal stalk, 3-7 mm long, and are glabrous, triangular 

 in cross-section; the 3 faces flat and or equal width or nearly so, and 15-30 mm (ca. 1 in) long. 

 Flowering in late June - early July. 



The combination of coarse, erect stems, short basifixed pubescence, and pendent pods that are 

 triangular in cross-section is diagnostic of this species in the Northern Great Plains. Manuals (Dom 

 1984, Great Plains Flora Association 1986) use the character of united stipules of the basal leaves to 

 key Astragalus racemosus, however, this character was not observable on Carter County plants 

 (growing stems had apparently split the cormection). Mature fruit are required to distinguish A. 

 racemosus from whitish flowered forms of two-groove milkvetch {A. bisulcatus). Pods of the latter 

 are flattened dorsiventrally (top to bottom) rather than trigonously; the dorsal side is convex and the 

 ventral side is doubly grooved or depressed. Drummond's milkvetch {Astragalus drummondii), 

 another coarse, whitish flowered milkvetch occurring in Carter County, differs by having foliage 

 with long spreading hairs. 



Note: We have been treating all collection records of raceme milkvetch in Montana as one variety, 

 Astragalus racemosus var. longisetus Jones, in keeping with Lesica and Shelly (1991). However, at 

 least one of these collections of Astragalus racemosus (Lesica #4565), from Carter County, has been 

 annotated by Rupert Bameby, specialist of the genus, as A. r. var. racemosus. This variety differs 

 from var. longisetus by having a shorter calyx (7.3-9 mm vs. 10-19 mm) and shorter calyx teeth (1- 

 3.5 mm vs. 5-10 mm), and by having narrower leaves (linear to elliptic vs. broadly elliptic to ovate- 



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