Astragalus Robbinsii var. Harringtonii

  • Title

    Astragalus Robbinsii var. Harringtonii

  • Author(s)

    Rupert C. Barneby

  • Scientific Name

    Astragalus robbinsii var. harringtonii (Rydb.) Barneby

  • Description

    7g. Astragalus Robbinsii var. Harringtonii

    Of moderate stature, the ascending stems (1) 1.5—3.5 dm. long; leaves 4—7.5 (10) cm. long, with 9-15 leaflets 5-23 mm. long, villous-pilosulous beneath with fine, loosely spreading or ascending, straightish, gray (sometimes partly fuscous or black) hairs up to 0.6-0.8 mm. long, either glabrous or thinly strigulose above; peduncles 6.5-15 cm. long; racemes rather densely 9-20-flowered, the axis little elongating, 1.5-3 (4) cm. long in fruit; calyx 6.1-8 mm. long, the tube 3.5-4.2 mm., the teeth 2.4-3.8 mm. long; petals pale purple or bluish-lavender; banner 9.5-11.5 mm., keel 7-7.6 mm. long; stipe of the pod 1.2-3 mm. long, the body subsymmetrically ellipsoid, 1.2-1.5 cm. long, 4-6 mm. in diameter, sometimes a little turgid, the valves densely villosulous with black hairs up to ± 0.5 mm. long, the septum relatively broad but incomplete, 1—1.6 mm. wide; ovules 6-8.—Collections: 8 (o); representative: J. P. Anderson 872 (US), 1787 (NY); Lt. York 113 (CAS, DS, MO, TEX); Frohne 49-52 (DS); Mrs. E. P. Walker 1058 (GH, US).

    Gravelly and turfy shores and river banks at low elevations, apparently uncommon, coastal southern and southwestern Alaska, from Glacier Bay westward to Goodnews Bay; reported from Kotzebue Sound (Hulten, 1943, p. 1087).—Map No. 5.—Late May to August.

    Astragalus Robbinsii var. Harringtonii (Rydb.), stat. nov., based on Atelophragma Harringtonii (George L. Harrington, in Alaska with U. S. Geological Survey) Rydb. in Bull. Torr. Club 55: 126. 1928.—"Alaska: Limestone ridge, Goodnews Bay, Harrington 60 (type ...flower), also at Matanuska, July 20, 1922, J. P. Anderson 1787 (fruit...)"—Holotypus, collected July 14, 1919, US!—Astragalus Harringtonii (Rydb.) Hult., Fl. Alaska & Yukon 1087, map 817. 1946. A. Harringtonii Cov. & Standl. ex Rydb., l.c., in syn.

    The Harrington milk-vetch is the form of A. Robbinsii most nearly deserving specific rank. The long, loose, and dense vesture of the lower leaf-surface, the relatively short and compact racemes, the long calyx-teeth, and wide septum within the pod form an exceptionally strong combination of characters in the context of the Oroboidei. However no single character of itself provides an infallible criterion, and whether one may prefer to emphasize or belittle the relationship to A. Robbinsii sens. lat. there can be no question that it is a close one. Rydberg described the flower as larger than that of related species of Atelophragma, but the petals are in reality no longer than in many examples of Cordilleran and eastern var. minor. Hulten (l.e.) accepted A. Harringtonii only hestitantly as specifically distinct from A. Macounii (our var. minor), of which he thought it might prove to be a coastal phase distinguished by a beakless pod and leaves more densely pubescent beneath and "punctuated" above. There is, however, no real difference in the form of the fruit; and the minutely whitish-tuberculate leaf- surface, although especially noticeable in var. Harringtonii, can be observed in less pronounced form in other varieties of A. Robbinsii. Mention has already been made of a plant found on the shores of Glacier Bay, apparently sympatric with genuine and typical var. Harringtonii, in which the thin pubescence and long stipe of var. minor (in its more northern Rocky Mountain and Alaskan phases) is combined with the long calyx-teeth and wide septum of var. Harringtonii. The latter has been interpreted provisionally as an outlying and somewhat aberrant form of var. minor; but whatever its real taxonomic status may be, it serves to tie var. Harringtonii firmly back into the A. Robbinsii complex.

    The locality-record as listed by Rydberg needs some correction. The plant from Glacier Bay (Anderson 1261, US) represents the ambiguous var. minor mentioned in the last paragraph. The collection from "Kobuls" ( = Kokuk) River (Palmer 658) is a robust form of A. alpinus. The Schrader plant from John River (US) is a Hedysarum.