Dalea candida var. oligophylla
Rupert C. Barneby
41a. Dalea candida Michaux ex Willdenow var. oligophylla (Torrey) Shinners
(Plate LVI)
Variable in habit of growth, (2.5) 3-7 dm tall, the stems nearly always diffuse, weakly virgate-ascending, or decumbent and distally incurved, branched from the middle upward, only subterminally, or almost throughout, the inflorescence therefore simply corymbose to amply paniculate, rarely monocephalous, the foliage mostly pallid or glaucescent, the leaflets not usually strongly bicolored, but often of slightly darker or more yellowish green above; stipules 1.5-3 mm long, usually more slender- tipped than in var. Candida; primary cauline leaves (1.5) 2-5 cm long, with either 5 or 7 leaflets varying in outline from obovate and emarginate to oblong and obtuse, lance-oblong or -elliptic and shortly acuminate (or merely gland-mucronate), the odd leaflet largest, up to (6) 9-20 (24) mm long; spikes 6-8 mm diam, the axis 1-5 (7.5) cm long; interfloral bracts 2.5-4 mm long; calyx either glabrous externally up to the internally pilosulous teeth or thinly minutely pilosulous from base upward, the intervals between the ribs charged at apex, on either side of the sinuses, with 1, 2, rarely 3 blister-glands; epistemonous petals 3.2-4.5 (4.7) mm long, the blades varying from elliptic to oblong or oblanceolate, either tapering or truncate basally, 2.3-3.1 mm long, (1.1) 1.2-2.6 mm wide; 2n = 14, n = 7 II (Mosquin).— Collections: 211 (vii).
Dry open places, in great variety of soils, entering many xeric plant-communities and many floristic provinces, in climax grassland mostly on breaks and stony or gravelly ridges and therefore not directly competing with sod-forming grasses, w.-ward from New Mexico descending into sandstone desert and ascending through pinyon-juniper woodland into yellow pine parklands, from ± 200 m (670 ft), in Iowa up to 1950 m (6500 ft) in Montana, to 2150-2250 m (7200-7500 ft) along the piedmont of the Front Range in Wyoming, Colorado, and Mesa de Maya in n. New Mexico, reaching 2400 m (8000 ft) on the White Mts. and Kaibab Plateau in Arizona, widely dispersed and locally common over the short-grass prairies from the South Saskatchewan in Alberta to the Assiniboine valley in s. Manitoba s., mostly w. of 97° W, to Red River in Oklahoma and trans-Pecos Texas, thence widespread over most of New Mexico into the canyonlands of the San Juan, Grand and Colorado rivers in s.-w. Colorado and s.-e. Utah, in Utah n. as far as San Rafael Swell in Emery County, and through the mountains and intermontane valleys of Arizona as far w. as the Kaibab and the Verde River, extending just into n.-e. Sonora, and discontinuously s. along the e. slope and piedmont of Sierra Madre Occidental to the sources of Rio Nazas in n.-w. Durango; in central United States e. on river-bluffs to the South Dakota-Minnesota boundary, to the Missouri bluffs in Iowa, to centr. Kansas, and e.-centr. Oklahoma; reportedly adventive on the Wisconsin bank of the .upper Mississippi in Buffalo County; cf. Wemple, 1970, map 6.— Flowering late May onward, in summer-rainfall areas of s.-w. United States and n. Mexico continuing into late fall. — Citation of representative var. oligophylla from U. S. and Canada superfluous. MEXICO. Sonora: typus of P. sonorae (cf. infra). Chihuahua: Shreve 7971 (ARIZ, F); Mexia 2621 (F, NY, UC); Pringle 1216 (MEXU); Ripley & Barneby 13,931 (NY). Durango: typus of P. truncatus (cf. infra).
Dalea Candida Michaux ex Willdenow var. oligophylla (Torrey) Shinners, Spring FI. Dallas-Ft. Worth 211. 1958, based on Petalostemon gracile ß oligophyllum (with few leaflets) Torr. in Emory, Notes Mil. Reconn. 139. 1848. - "Valley of the Del Norte."- Holotypus, collected near Albuquerque, New Mexico, by Lt. Emory, Sept 28, 1846, NY (herb. Torr.)!-Kuhnistera oligophylla (Torr.) A. Heller, Bull. Torrey Club 23: 122. 1896. Petalostemon oligophyllus (Torr.) Rydb., Mem. N. Y. Bot. Gard. 1 (Fl. Mont.): 237. 1900. P. candidus var. oligophyllus (Torr.) F. J. Hermann, Jour. Wash. Acad. Sci. 38: 237. 1948. Dalea oligophylla (Torr.) Shinners, Field & Lab. 17: 82. 1949.
Kuhnistera occidentalis (western) A. Heller ex Britton & Kearney, Trans. N. Y. Acad. Sci. 14: 33. 1895 (Jan/Feb). — "This is the Petalostemon candidus var. occidentalis Gray, in Pringle’s labels, but never described or published. Mrs. Hoyt, Ft. Apache; Wilcox, Ft. Huachuca." — Lectotypus, Pringle 1216, collected near Guerrero, Chihuahua, Sept 9, 1887, NY (2 sheets)! isotypi, F, GH! — P candidus var. occidentalis Gray ex Britt. & Kearn., Trans. N. Y. Acad. Sci. 14: 33. 1895, in syn., nom. nud. Kuhnistera candida occidentalis Rydb., Contrib. U. S. Nat. Herb. 3: 154. 1895 (Sept 14), an original and independent proposition based in part on Gray’s unpublished trinomial and Pringle 1216, best treated retroactively as an inadvertent comb. nov. Petalostemon occidentale (A. Hell.) Fern., Rhodora 39: 28. 1937.
Kuhnistera candida diffusa (spreading, of the stems) Rydb., Fl. Neb. 21: 59. 1895. — "Deuel County [ Nebraska], Rydberg 58. — Holotypus to be sought at NEB; isotypus, NY!
Petalostemon truncatus (square-cut, of the epistemonous petals) Rydb., N. Amer. Fl. 24: 124. 1920.— Type collected at Tepehuanes, Durango, June, 1906, Edw. Palmer 284..." — Holotypus, NY! isotypi, F, K. US!
Petalostemon sonorae (of Sonora) Rydb., N. Amer. Fl. 24: 125. 1920 ("Sonorae").—"Type collected at Rio de Santa Cruz, Sonora, June 25, 1855, Schott (Mex. Bound. Surv. no. 241, in part...)." — Holotypus, NY! isotypi, F, NY!
In everything but nomenclature and taxonomic rank my concept of var. oligophylla coincides with Petalostemon occidentale of Wemple’s revision (1970, pp. 43-47, fig. 9B); it will be unnecessary to review the segregates or the synonymy. A note on the still unidentified P. virgatum Nees, very likely to be referred here, will be found in Appendix I. The var. oligophylla is introduced first in order under D. Candida because it seems to constitute the major and more complex segment of its species, the var. Candida, adapted to a more uniform environment, being interpreted as the derived form, much poorer in detectable biotypes. This, however, may be an illusion, for all other close kindred of D. Candida have in common with it a compact flower-spike and dispersal on the Atlantic slope. It is worth remark that Wemple overstates at 6000+ ft the low elevational limit of var. oligophylla in New Mexico and Arizona. In the lower Rio Grande valley in New Mexico it descends to 4100 ft (1230 m), and in Arizona certainly to 4000, according to Kearney & Peebles to 3000 ft (900 m). The plants from higher and lower sites seem not to differ from each other or from the high- and low-level prairie forms, except in random and individual fashion. Some populations of var. oligophylla in Chihuahua have short and relatively dense spikes more or less corymbosely arranged. These suggest D. multiflora, but have the few leaflets of var. oligophylla. Other variation in the variety, implicit in the foregoing description, is discussed at length by Wemple and has been analyzed also by Isely & Welsh (1960).
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.Multimedia:
