(Plate LXX)

Perennial herbs, sometimes weakly suffrutescent in age, glabrous to the inflorescence or very rarely thinly villosulous distally, the 1-many terete or striate, stramineous or purplish, erect or virgately ascending stems (4) 5-13 dm tall, sparsely charged with immersed or some more prominent but never conspicuous glands, simple and leafy in the lower 2/3-3/4, thence paniculately or subcorymbosely branched, the foliage green or subglaucescent, the very numerous small leaflets punctate beneath; leaf-spurs very short or 0; stipules narrowly triangular to linear-subulate, livid, becoming dry and fragile in age; intrapetiolular glands 0 or minute; post-petiolular glands orange, not very prominent; leaves sessile or almost so, 1.5-5.5 cm long, with narrowly margined rachis and (8) 16-45 (48) pairs of linear to linear-oblong, obtuse or emarginate, involute leaflets 0.5-4 mm long crowded (0.5-2 mm apart) along the rachis on petiolules 0.1-0.45 mm long; peduncles 1-7 cm long (sometimes appearing longer due to suppression of upper leaves); spikes moderately dense, the flowers mostly 2-3-ranked when pressed, ovoid-conic or depressed-ovoid becoming cylindroid, without petals or androecia 7.5-10 mm diam, the densely villosulous axis becoming 0.3-6, mostly 0.5-2.5 cm long; bracts early deciduous, ovate or lance-acuminate, 2-3.5 mm long, livid, dorsally glandular, the lowest glabrous but the rest hirsutulous at least at base, sometimes nearly throughout, but the tips commonly glabrous; calyx densely silky-pilosulous with silvery hairs, 3.8-4.9 (5.8) mm long, the tube 2.2-2.5 (2.7) mm long, the brownish, subfiliform ribs not strongly salient, the membranous intervals charged with ± 2 irregular rows of small orange or yellowish glands, the triangular- acuminate, gland-spurred and -tipped teeth 1.2-2.2 (3.1) mm long, the dorsal one usually a little longer than the rest, only exceptionally longer than the tube; petals monochrome or somewhat bicolored, the banner then with a white but rubescent eye or transverse band, the epistemonous ones blue to blue-violet, rarely rose-lavender, perched much below middle of androecium, the banner sometimes charged with a gland-crescent and the inner petals rarely gland-tipped; banner 5.4-7.3 mm long, the claw 3-3.8 mm, the deltate-cordate blade 2.3-4 mm long, 3-4.2 mm wide; wings 5.1-8 mm long, the claw 1.8-3.3 mm, the ovate-elliptic blade 3.7-5 mm long, 1.8-2.5 mm wide; keel 6-7.4 mm long, the claws 2.3-3.2 mm, the broadly ovate blades 4.1-5 mm long, 2.6-3 mm wide; androecium 10-merous, 6.5-9.6 mm long, the longer filaments free for 1.4-2.4 mm, the connective gland-tipped; pod in profile obliquely obovate, 2.7-3 mm long, the style-base latero-terminal, the sutures subfiliform, the valves membranous at base, finely pilosulous and gland-sprinkled distally; seed 2-2.4 mm long; 2n = 14, 7 II (Mosquin).— Collections: 37 (vi).

Rocky hillsides in grassland and climbing into oak-madroño and pine-oak woodland, 1500-2550 m (± 5000-8500 ft), locally plentiful and rather common around the w. and s. margins of the Meseta Central from s.-centr. Durango to s.-e. Nayarit (Sa. de Palomas) and e. through Guanajuato into s. San Luis Potosi, in Jalisco descending to ± 1300 m in the barrancas of Rio Santiago downstream from Guadalajara and reappearing locally in w. Cordillera Neovolcanica (near Etzatlan and Cuautla).— Flowering July to October (November). —Representative: Durango: Gentry 6904 (F, GH, NY, US); Mosquin et al. 6833 (NY); Ripley & Barneby 13,482 (CAS, NY, MEXU), 14,190 (NY, US). Zacatecas: McVaugh 17,714 (MICH); Nayarit: Schubert & Souza 2059 (NY). Jalisco: Pringle 3835 (BR, F, NY, MEXU, UC, W, Z); Waterfall 13,833 (F, OKLA); McVaugh 13,665 (MEXU, MICH); Ripley & Barneby 14,134 (CAS, DAO, NY). Guanajuato: Kenoyer 2428 (GH); Ripley & Barneby 13,370 (CAS, MEXU, MICH, NY, US). San Luis Potosi: Parry & Palmer 146 (BR, F, NY, US).

Dalea pectinata (comblike, of the many, close-set leaflets) Kunth, Mimoses 169, pl. 49. 1819. — "Crescit in collibus prope Villalpando [Guanajuato] Mexicanorum, alt. 1330 hex." — Holotypus, P (herb. H. B. K. 4220)! — Parosela pectinata (Kunth) Rose, Contrib. U. S. Nat. Herb. 10: 104. 1906.

An attractive plant, notable for the ferny foliage, the leaves composed of very numerous (often 40-90) small narrow leaflets crowded along the rachis. All kindred or habitally similar species have leaflets either fewer, or broader, or pubescent. In general organization and stature D. pectinata resembles D. polystachya, the foliage of the virgate stems being abruptly reduced in amplitude where the primary axis branches into a panicle of rather loose narrow spikes. In both species the petals may be either blue or rose-purple, but in D. pectinata are usually a rich and vivid blue that turns violet-blue in drying. The peculiar grace and character of D. pectinata is superbly rendered in Turpin’s plate accompanying the protologue.