Dalea leucostachya

Rupert C. Barneby

54.  Dalea leucostachya Gray

(Plate LXIII)

Bushy shrubs of rounded outline, northward flowering as suffrutescent herbs and southward becoming tall straggling shrubs with thin naked trunks or (when old) small trees, fertile at stature of 0.4-6 m, varying from nearly glabrous to densely pilosulous or tomentulose almost throughout, the young branches pliant, freely forking, going out into ± pyramidal or corymbiform, leafless or sparsely leafy panicles of flexuous, catkin-like spikes; leaf-spurs 0.5-1 mm long; stipules deltate to subulate or lance-caudate, 1-3.5 mm long, becoming dry, fragile, and often easily rubbed off; intrapetiolular glands usually setiform, sometimes minute; post-petiolular glands prominent; main cauline leaves 2.5-9.5 cm long, shortly petioled, the rachis margined, shallowly grooved ventrally, punctate, the leaflets 3-7 pairs, oblanceolate to obovate, obovate-cuneate, or elliptic, emarginate to short-acuminate or obtuse and gland- mucronulate, flat or nearly so, (0.8) 1-2.5 (3) cm long, keeled dorsally, the leaves high on young fertile branchlets and leaves of axillary spurs developing contemporaneously with and after anthesis often smaller, with fewer and shorter, sometimes more densely pubescent leaflets; peduncles 0-3 cm long; spikes loosely and narrowly many- flowered, the flowers 2- or loosely 3-ranked when pressed, without petals 5-7.5 mm diam, the pilosulous axis (1) 1.5-8 cm, that of the central-terminal spike usually at least 3 cm long; bracts deciduous, ovate- or lance-acuminate, 1.2-2.5 mm long, submembranous, brown or purplish, dorsally pilosulous or puberulent, sparsely glandular; calyx 2.1-4 mm long, either puberulent to pilosulous externally from base upward or glabrous externally below the teeth, the tube 1.7-2.5 mm long, pleated when mature, the ribs prominent, castaneous or livid, the pale, submembranous intervals charged with 1 row of conspicuous or sometimes minute and colorless glands, the deltate to triangular teeth 0.4-1.5 mm long, commonly brown or nigrescent; petals white, the banner sometimes faintly rubescent, the wings and keel inserted below middle of androecium, the keel-petals united by their external edges but shorter than the stamens; banner 4.5-7.2 mm long, the claw 1.5-3.2 mm, the ovate-cordate, nearly erect blade 2.6-4 mm long, 2.4-4.4 mm wide; wings 3.4-7 mm long, the claws 0.7-2 mm, the elliptic or oblong blades not strongly auriculate, 2.7-5.3 mm long, 1.2-3 mm wide; keel 3.2-7.7 mm long, the claws 0.7-3 mm, the oblong-elliptic blades 2.7-5 mm long, 1.1-2.8 mm wide; androecium 10-merous, (4.5) 5-7.5 mm long, cleft ± half-way into a long tassel, the connective gland-tipped, the anthers golden-yellow, 0.4-0.7 mm long; pod in profile subaequilaterally triangular, ± 2-2.3 mm long, the style-base asymmetrically terminal, the sutures subfiliform, the valves very thin, green, at base glabrate, sprinkled with minute golden glands, pilosulous at tip; seed 1.1-1.4 mm long.

References: [Article] Barneby, Rupert C. 1977. Daleae Imagines, an illustrated revision of Errazurizia Philippi, Psorothamnus Rydberg, Marine Liebmann, and Dalea Lucanus emen. Barneby, including all species of Leguminosae tribe Amorpheae Borissova ever referred to Dalea. Mem. New York Bot. Gard. 27: 1-892.

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