Argus, Canad. J. Bot. 52: 1303, plate 1. 1974.
1.2-1.8 m, not clonal.
erect; branches gray-brown, glabrous; branchlets yellow-brown, glabrous.
stipules foliaceous; petiole 5-9 mm; largest medial blade narrowly elliptic, 32-58 × 12-19 mm, 2-3.3 times as long as wide, base cuneate or convex, margins slightly revolute, entire, apex acute to acuminate, abaxial surface glabrous, adaxial slightly glossy, glabrous; proximal blade margins shallowly serrulate; juvenile blade glabrous.
staminate 17.5-42 × 5-13 mm, flowering branchlet 6-7 mm; pistillate moderately densely flowered, stout, 20-40 × 6-12 mm, flowering branchlet 4-7 mm; floral bract tawny or bicolor, 1.3-2.5 mm, apex rounded, entire, abaxially glabrous.
abaxial nectary 0.3-0.8 mm, adaxial nectary narrowly oblong, 0.6-1 mm, nectaries distinct; filaments distinct, glabrous; anthers ellipsoid, shortly cylindrical, or globose, 0.4-0.7 mm.
abaxial nectary absent, adaxial nectary narrowly oblong or oblong, 0.5-1.1 mm, equal to or longer than stipe; stipe 0.4-1.2 mm; ovary pyriform, usually glabrous, rarely puberulent, beak slightly bulged below styles; ovules 12 per ovary; styles 0.6-0.8 mm; stigmas flat, abaxially not papillate with rounded tip, or broadly cylindrical, 0.3-0.5 mm.
Flowering late Jun. Thickets in moist, open forests, gravel floodplains; of conservation concern; 800-1500 m; Alta., B.C., N.W.T., Yukon.
. Thin-layer chromatography of leaf phenolics in
revealed a pattern similar to those of
(G. W. Argus, unpubl.). Based on overall similarity, its nearest neighbors are
, in a broad sense, and
(Argus 1997). The sectional placement of this species is uncertain. It is placed here in sect
because it clusters with
, but it is evidently close to
and may be a species of intersectional hybrid origin.