Astragalus johannis-howellii Barneby

Authors

Rupert C. Barneby

Authority

Barneby, Rupert C. 1964. Atlas of North American Astragalus. Mem. New York Bot. Gard. 13(1): 1-596.

Family

Fabaceae

Scientific Name

Astragalus johannis-howellii Barneby

Type

"California: near Owens River, east of Whitmore Tubs Springs, elevation about 7000 ft., in Long Valley, Mono County, 8 August, 1938, fl. & fr., John Thomas Howell 14383."—Holotypus, CAS! isotypus (fragm.), RSA!

Description

Species Description - Slender, diffuse, with a taproot and at length suffruticulose caudex, thinly strigose-villosulous with subappressed and loosely ascending, nearly straight hairs up to 0.4-0.5 mm. long, the herbage yellowish-green, the leaflets glabrous above; stems of the year prostrate or decumbent, 3-20 cm. long, freely branched or spurred toward the base, floriferous upward from below the middle; stipules scarious, 1.5-4 mm. long, all amplexicaul and connate, the lowest into a campanulate, subentire or shortly bidentate sheath, the upper ones through about half their length, with erect, triangular free blades; leaves 4—6 cm. long, with filiform but wiry petioles and (13) 15-23 distant, mostly scattered, oblong-oblanceolate, -elliptic, or narrowly obovate, obtuse, folded, readily deciduous leaflets, 1.5—6 mm. long, all jointed; peduncles ascending, very slender, 8—25 mm. long, shorter than the leaf; racemes very loosely 6—12-flowered, the flowers declined in age, the axis somewhat elongating, 1.5—4 cm. long in fruit; bracts membranous, triangular- ovate or lanceolate, 0.6—1.5 mm. long; pedicels very slender, 0.8—1.3 mm. long, at first ascending, in fruit a little arched outward but scarcely thickened or longer, bracteoles 0; calyx 2.9-3.8 mm. long, loosely white-strigulose, the subsymmetric disc 0.5 mm. deep, the campanulate tube 1.6—2 mm. long, 1.5—1.7 mm. in diameter, the narrowly subulate teeth 1.3—1.8 mm. long, the whole becoming papery, marcescent unruptured; petals whitish, immaculate; banner abruptly recurve through about 90°, ovate-cuneate, shallowly notched, 5—5.5 mm. long, 3.6-3mm. wide; wings 4.4-5.2 mm. long, the claws 1.4-1.7 mm., the oblong-elhptic, obtuse blades 3.4-3.9 mm. long, 1.4-1.8 mm. wide, the right one nearly erect, the left one strongly incurved from its junction with the claw; keel 3.3-3.9 mm. long, the claws 1.5-1.8 mm., the nearly half-circular blades 2.1-2.4 mm. long, 1.4-1.5 mm. wide, incurved through ± 110° to the sharply deltoid, minutely porrect apex; anthers 0.4-0.45 mm. long; pod pendulous, stipitate the slender stipe 0.5-2.5 long, the lunately oblong-ellipsoid or half-ellipsoid body 7 10.5 mm. long, 2.5-3 mm. in diameter, cuneately contracted at both ends, minutely cuspidate at apex, triquetrously compressed, carinate ventrally by the suture, the lateral angles narrow but obtuse, the lateral faces nearly flat, the dorsal faces nearly flat, the dorsal face deeply and openly sulcate, the thin, pale green, finely strigulose valves becoming papery-membranous, stramineous, delicately cross-reticulate, inflexed as a complete or almost complete septum ± 1 mm. wide; ovules 6-11; seeds brown or greenish-brown, sometimes faintly purple-dotted, minutely pitted, sublustrous, 1.6-2.4 mm. long.

Distribution and Ecology - Dry sandy ground among sagebrush, ± 7000 feet, known only from the neighborhood of the type-locality in upper Owens Valley, Mono County, California.—Map No. 53.—July to August.

Discussion

The Long Valley milk-vetch, A. Johannis-Howellii, may be described as a diminished version of A. Mulfordae, differing in the smaller size of nearly all parts, a shorter stipe, and fewer ovules. The species is evidently a rarity; for although native to a region which has been repeatedly and attentively botanized, it is still known only from three collections, possibly from only one population. The species was first identified as A. lentiformis, an equally rare astragalus endemic to Sierra and neighboring valleys in the northern Sierra Nevada, but is easily distinguished from this by its stipitate and triquetrous, not sessile and strongly compressed fruit. A third species with tiny, whitish flowers, A. Lemmoni, extends south to an isolated station in the upper Owens Valley and ocurs close to A. Johannis-Howellii, but in moist ground along streams. It may be recognized by its free stipules, flowers arranged in short, compact racemes on peduncles paired in most axils, and once again by a sessile pod.

Objects

Specimen - 675217, M. DeDecker 908, Astragalus johannis-howellii Barneby, Fabaceae (152.0), Magnoliophyta; North America, United States of America, California, Mono Co.

Distribution

California United States of America North America|