Bebb in J. M. Coulter, Man. Bot. Rocky Mt. 336. 1885.
Mountain or park or serviceberry willow
C. R. Ball var.
(Rydberg) C. R. Ball
branches yellow-brown or red-brown mottled with green, not or weakly glaucous, glabrous; branchlets red-brown to yellow-brown, glabrous or puberulent, pilose, or villous, (buds
stipules foliaceous or rudimentary on early ones, foliaceous on late ones, apex acute or acuminate; petiole shallowly grooved, or convex to flat adaxially, 5.5-14 mm, pilose, villous, or velvety to glabrescent adaxially; largest medial blade (sometimes amphistomatous), narrowly oblong to oblong, narrowly elliptic to elliptic, lanceolate, oblanceolate, or obovate, 35-95 × 11-33 mm, 2-3.9 times as long as wide, base convex, rounded, or subcordate, margins slightly revolute or flat, serrulate, serrate, or sinuate, apex acute to acuminate, abaxial surface glaucous, glabrous, adaxial dull, glabrous or pilose, midrib pilose to villous; proximal blade margins entire or serrulate; juvenile blade sometimes reddish, villous or long-silky abaxially, hairs white, sometimes also ferruginous.
staminate flowering before or just before leaves emerge, pistillate as leaves emerge; staminate stout, 14-39 × 9-17 mm, flowering branchlet 0.5-7 mm; pistillate densely flowered, stout, 21-60 × 8-16 mm, flowering branchlet 0.5-8 mm; floral bract brown, black, or bicolor, 1-2 mm, apex rounded to acute, abaxially hairy, hairs wavy, straight, or curly.
adaxial nectary narrowly oblong, 0.6-1.1 mm; filaments distinct or connate less than 1/2 their lengths, glabrous; anthers purple turning yellow, 0.4-0.8 mm.
adaxial nectary narrowly oblong, oblong, or flask-shaped, 0.4-1 mm, shorter than or equal to stipe; stipe 0.5-1.6 mm; ovary pyriform, glabrous, beak gradually tapering to styles; ovules 11-15 per ovary; styles 0.6-1.1 mm; stigmas flat, abaxially non-papillate with rounded tip, or broadly cylindrical, 0.24-0.36-0.56 mm.
Flowering late Apr-early Jul. Streams, cienegas, meadows, springs; 1700-3500 m; Ariz., Colo., N.Mex., Utah, Wyo.