123.  Dalea wigginsii Barneby

(Plate CXI)

Slender divaricately branching shrubs up to 5 dm tall, the old stems becoming furrowed and corky, the primary axes arcuate-recurved but not (or only exceptionally) tip-rooting, the wiry secondary ones shorter, ± erect, castaneous or purplish, thinly glandular but not verruculose, like the foliage villosulous with fine spreading-ascending hairs up to 0.15-0.5 mm long, the leaflets brighter green above (exceptionally glabrescent), punctate beneath, the inflorescences silky-villosulous; leaf-spurs up to 0.5 mm long; stipules triangular-subulate, 0.5-2.5 mm long, livid-castaneous becoming papery, thinly puberulent; intrapetiolular glands 0; post-petiolular glands small but prominent, conic; leaves short-petioled, the main cauline ones all subtending leaf- spurs or branchlets, drought-deciduous, 5-10 mm long, mostly shorter than the internodes, with very narrowly margined rachis and (3) 4-9 (10) crowded pairs of narrowly oblanceolate, ± involute, dorsally carinate, usually gland-mucronulate leaflets (1) 1.5-3.5 mm long, the terminal one sessile, the leaves of spurs smaller, with fewer shorter leaflets; peduncle terminating each primary axis up to 3.5 cm long, of axillary spurs almost 0; spikes relatively loose and few-flowered, ovoid becoming narrowly oblong, 8-10 mm diam without petals, the flowers (pressed) falling into 2-3 ranks, the pilosulous axis finally 5-15 mm long; bracts deciduous (the lowest tardily), ovate to lanceolate, 2-4.5 mm long, green or purplish-castaneous, pilosulous and glandular dorsally, glabrous within; calyx 4-4.5 mm long, softly pilosulous with fine spreading spiral hairs up to 0.7-1 mm long, the tube 2.1-2.5 mm long, the ribs at anthesis immersed, later prominulous, the submembranous intervals charged with 1 row of ± 3 small transparent or brownish glands, the ovate-triangular, shortly acuminate or mucronate, minutely spurred, livid or brownish teeth 1.8-2.1 mm long; petals bicolored, the banner pale yellow, early rubescent, its blade charged with a gland- crescent, the epistemonous ones perched low on the androecium, 0.5-1.3 mm above hypanthium, the blades bright purple, the keel gland-tipped; banner 5.2-6.7 mm long, the claw 2.4-3.1 mm, the hooded blade 2.8-3.3 mm long, recessed at base into a cornet, 3.9-4.2 mm wide; wings 4.8-5.7 mm long, the claw 1.2-1.9 mm, the elliptic or obliquely ovate blade 3.2-4.7 mm long, 1.6-2.4 mm wide; keel 6.4-7.8 mm long, the claws 2.6-3.5 mm, the broadly obovate blades 3.9-4.9 mm long, 2.4-3 mm wide; androecium (9) 10-merous, 6.5-7 mm long, the longer filaments free for 2-2.6 mm, the connective gland-tipped, the pallid anthers 0.65-0.9 mm long; pod and seed unknown. — Collections: 4 (ii).

Stony hillsides and rock-debris under cliffs, in pine-oak forest, 2100-2430 m (7000 -8100 m), known only from Sierra Madre Occidental in s.-w. Durango (from ± 50 km s.-w. of Ciudad Durango to El Salto). — Flowering October to April. —Material: Durango. 29 mi s.-w. of Cd. Durango (near Los Mimbres), Ripley & Barneby 13,489 (NY); 31 mi s.-w., cf. typus; 35 mi s.-w., Ripley & Barneby 14,191 (CAS, MEXU, NY, US); El Salto, Wiggins 13,202 (SD).

Dalea wigginsii (Ira Loren Wiggins, 1899- ) Barneby, sp. nov., D. versicolori Zucc. forsan propiuscula sed ab omnibus suis formis calycis breviter pilosuli dentibus abbreviatis nec aristiformibus, spica brevi pauciflora, foliis parvis paucifoliolatis, habituque dif- fuso absimilis. A D. radicanti Wats, habitu subsimili imprimis foliis griseo-pilosulous nec glabris, inflorescentia spicata nec racemulosa, calycisque pube distantior videtur. — Durango: 31 mi w. of Cd. Durango on route 40, March 6, 1966, W. Hess & M. T. Hall 545.—Holotypus, MICH.

This charming little shrubby dalea is, like most varieties of the polymorphic D. versicolor, seasonally dimorphic. In October and November, following summer rains, the plants are in full vigor, the new growth is still well clothed in leaves, but there are as yet few flowers, these all borne in pedunculate spikes terminal to the wiry, divergent or trailing main stems. During winter, a period of drought and cold, the primary cauline leaves drop off, but growth continues in the form of axillary spurs, often incurved to vertical, each of which goes out eventually into a few-flowered, sessile spike or head. It is not until March or April that the plant reaches flowering peak, when all larger leaves are shed and every last twig carries a few prettily bicolored flowers, the banner yellow fading reddish, in contrast to pink-purple wings and keel. In general aspect D. wigginsii suggests a diminished D. versicolor, with greatly condensed foliage and contracted spikes, but it differs more significantly in the shortly pilosulous, broadly short-toothed calyx charged between the less prominent ribs with inconspicuous glands. Occasional stems of D. wigginsii root where they arch downward to touch the ground, and the plant then assumes the growth-habit of D. radicans, distantly allopatric at the far eastern edge of Meseta Central. This differs further in its glabrous stem and foliage, racemose not spicate inflorescence, and different vexillar structure. The species is dedicated to a distinguished student of Dalea in the Sonoran Desert, who was first to collect it, near El Salto, March 19, 1955.