Astragalus lentiginosus var. macrolobus (Rydb.) Barneby
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Authors
Rupert C. Barneby
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Authority
Barneby, Rupert C. 1964. Atlas of North American Astragalus. Mem. New York Bot. Gard. 13(2): 597-1188.
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Family
Fabaceae
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Scientific Name
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Type
"Type collected at West Humboldt Mountains, Nevada, June, 1868, Watson 254 in part (Torrey Herbarium)." Holotypus, NY!
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Synonyms
Cystium macrolobum Rydb., Cystium vulpinum Rydb.
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Description
Variety Description - Growth-habit and appearance of var. salinus, but villosulous with spreading and ascending, sinuous or curly, and sometimes some longer, straighter hairs up to 0.5-0.9 (1) mm. long, the herbage cinereous or greenish, the leaflets commonly pubescent on both sides or (transition to var. salinus) glabrate and ciliate; leaves 4-11 cm. long, with (9) 13-19 leaflets 4-20 mm. long; peduncles 2.5-7 cm. long; racemes (8) 12-30-flowered, loose or early becoming so, the axis (2) 3-7 (9) cm. long in fruit; calyx white- or partly black-villosulous, (4.5) 5-7.1 mm., the tube 3-3.8 mm. long, 2-2.6 mm. in diameter, the teeth (1.5) 2-3.3 mm. long, often spreading-recurved; petals whitish (exceptionally purple); banner 9.3-11.3 mm. long; wings 8.3-9.5 mm. long; keel 6.5-8 mm., the claws 3.7-4.5 mm., the blades 3.2-4.2 mm. long; pod as in var. salinus, 1.5-2.5 cm. long, (6) 8-14 mm. in diameter, pale green or sometimes faintly mottled, glabrous or strigulose; ovules 18-26.
Distribution and Ecology - Sandy valleys, dunes, and sagebrush plains and hillsides, ± 3800-5600 feet, locally abundant in the lower Humboldt River and Quinn River Valleys in Humboldt, Pershing, Lander, and Churchill Counties, Nevada, passing north and east into var. salinus and west into var. floribundus.—Map No. 127.—April to July.
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Discussion
The var. macrolobus might possibly be passed over as a third pubescence-phase of var. salinus, coordinate with the nearly glabrous and cinereously strigulose ones already described, for it differs consistently in no other character. However the means of variation in length of fruiting raceme and calyx-teeth are substantially higher, and the variety, as defined primarily by its villosulous vesture, occupies an extensive area to the exclusion of its close relative. In my revision (1945, p. 89) I included in the description and exsiccata a number of specimens from Elko and Washoe Counties which differ from var. macrolobus, as redefined here, in their thinner or appressed pubescence or in the condensed raceme. I must now refer those that I have examined once again to var. salinus and var. floribundus respectively, although each is atypical in one or more characters. Intergradation with the ashen form of var. salinus, especially in southern Harney and Malheur Counties, and in southern Idaho eastward as far as Twin Falls County, has been mentioned under var. salinus. The pod of var. macrolobus may be either glabrous or pubescent (the latter is Cystium vulpinum), sometimes in a population of otherwise similar plants. On account of its loose raceme of small flowers and villosulous herbage, var. macrolobus closely mimics some forms of var. Fremontii, the range of which lies, however, much farther southward. A rare form of var. macrolobus with purple flowers is technically indistinguishable from var. Fremontii. It has been collected twice, by Jones at Rose Creek in Humboldt County, and by Mrs. Van Dyke somewhere along the Victory Highway between Elko and Winnemucca. Jones’s collection is partly purple- and partly white-flowered.
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Objects
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Distribution
Nevada United States of America North America| Oregon United States of America North America|