3.  Dalea simulatrix Barneby

(Plate XXX)

Slender humifuse perennial herbs with the habit of D. neo-mexicana, with several or numerous flexuous, simple or distally 1-branched, usually purplish and sparsely gland-tuberculate stems (1) 1.5-2.5 dm long radiating from an eventually woody root, softly and densely villosulous throughout with fine, spreading and widely ascending hairs, the foliage ashen, the leaflets equally pubescent both sides, punctate beneath and marginally, their margins commonly somewhat undulate; leaf-spurs almost 0; stipules thinly herbaceous, lanceolate or subulate, 1-2.5 mm long, villous and glandular dorsally; intrapetiolular glands 0; post-petiolular glands prominent, obtuse, pale yellow, often situated not precisely behind the petiolule; leaves shortly petioled, (0.6) 1-2 cm long, with very narrowly margined rachis and (3) 4-7 pairs of obovate, oblong-obovate, or obovate-cuneate, apically rounded or emarginate, loosely folded or navicular, dorsally keeled leaflets 2-7 mm long, the terminal one sessile and smaller than the last pair; peduncles mostly terminal, or 1 terminal and 1 leaf-opposed, 2-4.5 cm long; racemes dense, ovoid becoming oblong, when pressed at full anthesis 16-19 mm diam, the villosulous axis becoming 1.5-4.5 cm long; bracts deciduous, narrowly ovate- to lance-acuminate, thinly herbaceous becoming papery, 4-5.5 mm long, 0.7-2 mm wide, ± navicular, densely villosulous and charged with a few glands dorsally, glabrous within; pedicels 0.2-0.5 mm long, the prickle-glands at base and apex 0.3-0.5 mm long, livid; calyx 6.8-8.5 mm long, densely silky-pilose with spreading- ascending spiral hairs up to 1.6-2.7 mm long, the tube 3.1-3.5 mm long, not recessed behind banner, the ribs slender, prominulous, livid or pinkish, the membranous intervals charged with 1 row of (1) 3-5 small orange glands, the deltate-aristate, finally spreading and long-plumose teeth 3.7-5.3 mm long; petals ± bicolored, whitish with inner half of wings and keel-tip pink-purple, all gland-sprinkled, the epistemonous ones perched well below middle of androecium and all deciduous; banner 6.3-7.3 mm long, the claw 2.7-3.5 mm, the deltate-cordate blade 4-4.7 mm long, 4-4.4 mm wide; wings 6-7.1 mm long, the claw 1.5-1.9 mm, the lance-ovate blade 4.5-5.3 mm long, 1.8-2.6 mm wide; keel (6) 6.2-7.5 mm long, the claws 2-2.5 mm, the obliquely obovate blades 4.2-5.2 mm long, 2.5-3.2 mm wide, the inner margins undulately puckered; androecium 10-merous, 7.3-8.5 mm long, the longer filaments free for 2.2-2.6 mm, the connective gland-tipped, the anthers 0.8-1 mm long; pod obovoid, strongly compressed, it 3 mm long, the style-base obliquely terminal, the prow thickened, narrowly bicarinate, the valves hyaline in lower 1/3 thinly pilose and papery distally; seed ± 2.3 mm long; 2n = 16 (Mosquin). — Collections: 4 (ii).

Open calcareous gravel hills and gravelly or chalky gullied bluffs in arid grassland, sometimes with juniper, ± 1750 m (5800-5850 ft), local but forming colonies, in all known stations associated with D. verna, on the e. piedmont of Sierra Madre Occidental in s.-centr. Chihuahua (mpo Hidalgo del Parral) and adjoining Durango (mpos Villa Ocampo and Villa Hidalgo). —Flowering September to November, probably again in spring. —Material: Chihuahua. Hidalgo del Parral: 5 mi w. of Parral, Mosquin 6920 (NY), Ripley & Barneby 13,927 (CAS, NY, US). Durango. Villa Ocampo: cf. typus; Villa Hidalgo: 30 mi s.-e. of Las Nieves, Mosquin 6916 (DAO, p.p., mixed with D. verna).

Dalea simulatrix (aping D. neo-mexicana) Barneby, sp. nov., D. neo-mexicanae Gray affinis, praesertim floris majusculi carina decidua nec marcescenti, carinae laminis majori- bus 4.2-5.2 (nec 2.4-3.4) mm longis absimilis.—Durango; gravelly and chalky bluffs along stream, with junipers, in rolling grassland, 1755 m, ± 18 km (12.5 mi) s.-e. of Villa Ocampo, oct 4, 1965, Ripley & Barneby 13,944. — Holotypus, NY.

This local species may be visualized as a large-flowered version of D. neo-mexicana, to which it is obviously closely akin. It would have been subordinated to D. neo-mexicana as a fourth variety except for the fact that the keel as well as the wings disjoint from pockets on the androecium. In this feature it resembles D. mollis and D. mollissima, but is perennial and native to the cool dry highlands at the east foot of Sierra Madre Occidental, not the torrid lowlands of the Sonoran Desert. A minor differential character is found in the epistemonous petals, the blades of which are sprinkled with glands well above the base. The known ranges of D. neo-mexicana var. neo-mexicana and D. simulatrix are separated by a discontinuity along the foot of the Sierra equal to a degree of latitude. The less similar D. neo-mexicana var. megaladenia is found a similar distance eastward in the same latitudes but out on the floor of the Chihuahuan Desert. A supposed hybrid between D. simulatrix and its compatriot D. verna is mentioned under the latter species.