56.
Atriplex confertifolia
(Torrey & Frémont) S. Watson, Proc. Amer. Acad. Arts. 9: 119. 1874.
Shadscale
Obione
confertifolia
Torrey & Frémont in J. C. Frémont, Rep. Exped. Rocky Mts., 318. 1845;
Atriplex
collina
Wooton & Standley;
A. subconferta
Rydberg;
O. rigida
Torrey & Frémont
Shrubs,
dioecious, 3-8 dm, spinescent.
Leaves
persistent, alternate; petiole 1-4 mm; blade orbiculate to ovate, elliptic, or oval, 9-25(-45) × 4-20(-25) mm, margin entire, apex obtuse.
Staminate flowers
yellow, in clusters 2-4 mm wide or in spikes to 1 cm, axillary, in foliose-bracteate, divaricately branched panicles 3-15 cm.
Pistillate flowers
in similar paniculate inflorescences.
Fruiting bracteoles
sessile or subsessile, suborbiculate to rhombic or elliptic, 4-12 mm and wide, body indurate, terminal teeth distinct, foliaceous, shorter than bracteoles, entire or toothed below, terminal teeth spreading at maturity, faces smooth, lacking appendages.
Seeds
1.5-2 mm wide.
2
n
= 18, 36, 54+.
Flowering spring-fall. Gravelly to fine-textured soils in greasewood, mat-atriplex, other salt desert shrub, sagebrush, pinyon-juniper, and ponderosa pine communities; 600-2200 m; Ariz., Calif., Colo., Idaho, Mont., Nev., N.Mex., N.Dak., Oreg., Tex., Utah, Wyo.
Shadscale forms hybrids with
Atriplex canescens, A
.
garrettii, A
.
corrugata
, and
A
.
gardneri
varieties. It is, however, closely allied to
A. parryi
and
A. spinifera
. The plants are widely dispersed, typically on saline substrates but less commonly on essentially non-saline ones, through large areas of the western United States and adjacent Canada and Mexico, on both raw and exposed geological strata and on alluvium.
