Astragalus convallarius var. scopulorum

  • Title

    Astragalus convallarius var. scopulorum

  • Authors

    Rupert C. Barneby

  • Scientific Name

    Astragalus convallarius var. scopulorum Barneby

  • Description

    50c. Astragalus convallarius var. scopulorum

    Similar to var. convallarius, but sometimes quite thinly strigulose and greenish, the leaflets more often glabrous above, and the lower leaves more often bearing up to 6 pairs of petiolulate leaflets up to 1-20 mm. long; racemes (2) 14-25- flowered; pedicels at anthesis (1.6) 2-3 mm., in fruit (2) 2.5-4.5 mm. long; bracteoles 0-2; calyx 4-6.3 mm. long, black- or partly black-strigulose, the tube (3.5) 3.8-5.4 mm. long, (2.2) 2.5-3.1 mm. in diameter, the teeth 0.5-1.1 mm. long; petals bright pink-purple, or whitish tinged with pinkish-lavender, rarely ochroleucous and purple-veined; banner (6.6) 8.1—11.2 mm. long; wings (7) 9.1-12.6 mm. long; keel (6.2) 6.5-9 mm. long, its blades 3.5-4.8 mm. long, 2.2—2.6 mm. wide; pod oblanceolate in profile, tapering downward from near the obliquely triangular apex, 2—3.5 cm. long, 2.3—4 mm. in diameter just below the end; ovules 11—17; seeds 1.8-3.5 mm. long.—Collections: 21 (vii); representative: Parry 52 in 1864 (NY, POM); W. A. Weber 3337 (CAS, RSA, WS), 4894 (CAS, OKLA, SMU, TEX, WS); C. F. Baker 242 (ND, NY, RM, WS); Ripley & Barneby 5429 (CAS, RSA).

    Dry hillsides, gullied banks, and sandy flats, commonly in sagebrush, sometimes in oak woodland, or with pinon and juniper, 5800-8200 feet, locally plentiful and rather common on the west slope of the Colorado Rocky Mountains, from the White River south to the Gunnison, Rio Blanco to Gunnison County, extending east up the Rio Grande to Middle Park.—Map No. 22.—May to July.

    Astragalus convallarius var. scopulorum (of rocks, or by convention of the Rocky Mountains) Barneby in Leafl. West. Bot. 5: 30. 1947.—"Colorado: ... 25 miles n. of Loma, Garfield Co., 28 May, 1943, fl. & fr., Ripley & Barneby 5478"—Holotypus, CAS! isotypus, RSA!

    (?) Homalobus salidae (of Salida) Rydb. in Bull. Torr. Club 32: 667. 1905 ("Salidae").— "Colorado: Salida, August 3, 1896, C. L. Shear 3468."—Holotypus, NY!—Pisophaca salidae (Rydb.)Rydb. in N. Amer. Fl. 24: 325. 1929.

    In Gray’s annotated copy of his Revision (1864, p. 230, in my library) a note is penciled in his hand against A. junceus, showing that he had recognized this species, known hitherto only from Nuttall’s typus, in specimens received from the Colorado Rockies, collected by Parry in the same year, in lat. 39—41° N. These are the same Parry specimens cited above as representative of var. scopulorum and belong to an entity apparently confined to a small area of the Colorado River watershed lying well to the south of Nuttall’s transcontinental route. The average plant of var. scopulorum is greener than var. convallarius ( = A. junceus Gray), leafier (with better developed, distinctly jointed leaflets in some early leaves), and at least in the Gunnison and lower Grand River Valleys handsomely purple-flowered; but its best differential character is the oblanceolate rather than linear or linear-acuminate pod which tapers downward very gradually into the calyx from a broad, obliquely triangular apex. In Middle Park and on the White River this characteristic fruit is combined with dingily purple-tinged petals and the sparsely leafy growth-habit of var. junceus, and it seems that the two varieties are fully intergradient in northwestern Colorado. The fruits of var. scopulorum and of the sympatric A. miser var. oblongifolius are almost identical in form. Occasionally the two species are found growing together, but they are easily told apart by the position of the root-crown, the different curvature of the petals, and the shape of the keel.

    The reduction of H. salidae to var. scopulorum is not satisfactory and may require correction. The unicate holotypus of H. salidae consists of a single stem branching upward from the leafless base and is similar in many respects to var. scopulorum; but some lower leaves are composed of up to 21 jointed leaflets, and the pod is extremely slender, scarcely 2 mm. in diameter, becoming subterete when distended by the seeds. The very long pedicels are suggestive of a "grallator" freak (cf. discussion under A. bisulcatus), even through the plant is otherwise to all appearances normally developed. The type locality is in the upper Arkansas Valley, thus on the east slope of the Divide from which we have no other example of var. scopulorum, and we question whether H. salidae may represent a distinct form. Jones (1923, Index) listed H. salidae as a synonym of his A. campestris ( = our A. miser), and it is possible that the typus really does represent one of the protean manifestations of A. miser var. oblongifolius. C. L. Porter (1951, p. 30) referred it doubtfully to A. diversifolius, a concept which included the present A. convallarius. Rydberg’s transfer of H. salidae to Pisophaca, because of the almost terete ripe pod, has no apparent bearing on its relationships.