Dalea grayi

  • Title

    Dalea grayi

  • Authors

    Rupert C. Barneby

  • Scientific Name

    Dalea grayi (Vail) L.O.Williams

  • Description

    12.  Dalea grayi (Vail) L. O. Williams

    (Plate XXXVII)

    Perennial herbs from a woody root and finally a short caudex, glabrous below the spikes, (3) 3.5-7 (9) dm tall, the erect or commonly assurgent, angulately ribbed, glandless or remotely and minutely punctate, pale green or later stramineous but not or obscurely pruinose stems paniculately branched from near the middle, the spikes terminating all branches, the sparse foliage green, the thick-textured leaflets punctate beneath; leaf-spurs 0.4-0.9 mm long; stipules narrowly subulate, 0.4-1.3 mm long, rigid, yellowish; intrapetiolular glands obsolete; post-petiolular glands small, commonly impressed; leaves 1-5 cm long, shortly petioled, with narrowly margined, commonly punctate rachis and (5) 8-21 pairs of elliptic-oblanceolate to narrowly obovate, acute, obtuse, or obtuse and mucronulate, loosely folded leaflets 1-4.5 (5.5) mm long, these usually ascending along the rachis; peduncles 0.5-5 (10) cm long; spikes dense but not conelike, narrowly conic-ovoid to cylindroid, or the smallest remaining subglobose, without petals 7-9 mm diam, the densely villosulous axis becoming (0.4) 0.7-5.5 (7) cm long; bracts persistent (falling with, the fruit), rhombic-obovate to ovate- or lance-acuminate, (2.2) 2.5-4.5 mm long, 0.8-1.4 mm wide, rather firm, shallowly boat-shaped, densely ciliolate, all but the lowest pubescent dorsally, brownish to livid and purple-glandular distally; calyx densely silky pilosulous, 3.6-4.8 (5.2) mm long, the tube 2-2.7 mm long, its orifice subsymmetrical, the orange-brown ribs becoming prominent, the membranous intervals charged with one row of 3-6 small, pale yellow glands, the triangular, shortly acuminate-aristate teeth 1.3-2.4 (3.2) mm long, shorter than, equalling, or exceptionally a trifle longer than the tube; petals white, the faintly greenish blade of the banner finally rubescent, the epistemonous petals perched at or up to 0.5 mm below separation of the filaments, the inner pair free from the first; banner 4-5.7 mm long, the claw 2.4-3.2 mm, the rhombic-ovate to deltate-cordate blade 1.6-2.5 mm long, 2-2.4 mm wide; wing- and keel-petals sub- homomorphic but the inner pair sometimes a trifle wider and more oblique, the oblong, oblanceolate, or obliquely obovate blades 2.2-3.1 mm long, 0.8-1.4 mm wide, contracted at base into a claw 0.2-0.5 mm long; androecium 10-merous (one stamen sometimes barren) 5.5-7 mm long, the filaments free for 2.7-4 mm, the connective gland-tipped, the pale yellow anthers 0.55-0.7 mm long; pod triangular-semiobovate in profile, 2.2-2.5 mm long, the style-base terminal, the prow prominent, somewhat thickened, the valves hyaline at base, thinly papery, villosulous and finely gland- sprinkled distally; seed (little known) ± 1.6 mm long; 2n =7 II (Mosquin).— Collections: 31 (ii).

    Open slopes and stony flats in oak-pine or oak woodland, e.- and n.-ward coming out into grama grassland of the foothills, 780-2160 m (2600-7200 ft), locally common along the e. slope and crest of Sierra Madre Occidental from headwaters of Rio de Ramos in Durango (mpos Santiago Papasquiaro and Sta. Catarina de Tepehuanes) n. through Chihuahua to s.-e. corner of New Mexico (Grant and Hidalgo cos.), w. rather abundantly to headwaters of the Gila River in s.-e. and (one station) e.-centr. Arizona (Natanes Plateau, Gila County), more rarely across the Sierra Madre divide to scattered stations on the Pacific slope in n. and s. Sonora (Rios Santa Cruz and Bavispe; Rio Mayo) and centr. Sinaloa (Sa. Surutato and Cerro Colorado, near 25° 10-50' N).— Flowering June to December. — Representative: Arizona: Maguire 13,058 (NY, UC); Jones 24,898 (NY, POM); Barneby 5140 (NY); Lemmon 2672 (UC). New Mexico: Metcalfe 684 (NY, US); Bigelow 228 (NY). Sonora: S. S. White 2686 (MICH); Gentry 503 Mb (MICH). Chihuahua: S. S. White 2579 (ARIZ, MICH); Townsend & Barber 283 (F, MEXU, NY, Z); Pringle 642 (BR, F, NY, W); Ripley & Barneby 13,889 (CAS, NY, US); Gentry 8240 (MEXU, UC, US). Durango: Mosquin 6889 (NY); Palmer 283 (C, F, GH, NY, UC). Sinaloa: Gentry 5180 (NY); Breedlove 16,976 (NY).

    Dalea grayi (Vail) L. O. Wms., Ann. Missouri Bot. Gard. 23: 450. 1936, based on Parosela grayi (Asa Gray, 1810-1888) Vail, Bull. Torrey Club 24: 14. 1897, a legitimate substitute for Dalea laevigata (smooth) Gray, Pl. Wright. 2: 38. 1853. — "On the Chiricahui Mountains, and on the Barbocomori, Sonora [now Arizona]; Aug., Sept. (989)."- Lectoholotypus, collected in 1851 by Charles Wright, GH! isotypus, NY! paratypus, Thurber 944 from Sta. Cruz, GH! —Non Dalea laevigata S. & M. ex G. Don, 1832. — Parosela grayi (Vail) Rydb., N. Amer. Fl. 24: 119. 1920.

    Through the large part of its range lying along the east slope and crest of Sierra Madre from central Durango into southeastern New Mexico, and west of the divide in southern Arizona and adjoining Sonora, Dalea grayi is the only white-flowered member of its group. A plant of modest stature (rarely over 6-7 dm tall), it is easily recognized by the combination of sparsely leafy stems, many small leaflets of thick texture ordinarily displayed at a narrow angle to the rachis, and softly pilosulous spikes of small, fleeting flowers of characteristic Thornbera structure. In Arizona and adjacent Sonora its range overlaps that of D. pringlei var. pringlei, distinguished by relatively long calyx-teeth, vivid magenta-purple petals, and leaflets of prevailingly broader, blunter type. It is only on the west slope of the Sierra, at moderate altitudes, where the ranges of D. grayi, D. revoluta, and complex forms of D. pringlei coincide in range, that problems of identification are likely to arise in practice. Generally, however, D. revoluta may be distinguished immediately by its fewer, very narrow leaflets, while sympatric varieties of D. pringlei that are white-flowered have virgate stems over a meter tall. For details see discussion of the next two species following.