Antennaria rosulata Rydb. (redirected from: Antennaria bakeri)
Family: Asteraceae
[Antennaria bakeri Greene,  more...]
Antennaria rosulata image

Dioecious. Plants 0.2-1.5(-2) cm. Stolons 1-2(-3.5) cm. Basal leaves 1-nerved, spatulate, spatulate-obovate, or oblanceolate, 6.5-13 × 2-5 mm, tips mucronate, faces silvery gray-pubescent (often obscurely stipitate-glandular). Cauline leaves linear, 2-9 mm, not flagged (apices acute). Heads usually borne singly (rarely 2-3; subsessile among basal leaves). Involucres: staminate 5-7.5 mm; pistillate 6-10 mm. Phyllaries distally white. Corollas: staminate 2.5-4.5 mm; pistillate 3.5-5.5 mm. Cypselae 0.8-1.5 mm, papillate (bases puberulent); pappi: staminate 3.5-5 mm; pistillate 5.5-6.5 mm. 2n = 28.

Flowering summer. Open slopes and dry meadows, lower montane to montane, or subalpine zone, usually with big sagebrush, Artemisia tridentata; 2200-3300 m; Ariz., Colo., N.Mex., Utah.

Antennaria rosulata is easily recognizable by its silvery gray leaves, dense, humifuse growth form, and heads borne singly (R. J. Bayer 1987b). Its distribution is centered on the four corners area (Bayer and G. L. Stebbins 1987). It has probably contributed to the origins of some of the clones of A. rosea with low stature and low numbers of flowering heads that are found in Arizona, Colorado, New Mexico, and Utah.

Duration: Perennial

Lifeform: Forb/Herb

General: Perennial, 0.2-2 cm tall, mat-forming; plants acaulescent or shortly caulescent; stolons 1-3.5 cm long.

Leaves: Basal and cauline, alternate, the basal leaves spatulate to oblanceolate, 6.5-13 mm long, 2-5 mm wide, 1-veined, surfaces silvery-gray pubescent, often inconspicuously stipitate-glandular, apex mucronate, cauline leaves linear, 2-9 mm long; blades sessile.

Flowers: Heads 2-7, in corymb-like arrays, staminate and pistillate flowers on separate plants; phyllaries white, pink, green, reddish, or brown at the tips; disk flowers only; involucre of staminate heads 5.5-7.5 mm long, corolla 3.5-4.5 mm long; involucre of pistillate heads 8- 15 mm long, corolla 5-8 mm long; flowers May-August.

Fruits: Achene, 0.8-1.5 mm long, the surfaces with minute bump- like projections, puberulent at the base; pappus of staminate heads 3.5-5 mm long, of pistillate heads 5.5- 6.5 mm long.

Ecology: Forests, meadows, open slopes, subalpine communities; 1600-3700 m (5500-12000 ft); Apache, Coconino, and Yavapai counties; southwestern U.S.

Notes: Antennaria rosea (rosy pussytoes) is similar to A. rosulata, but it is taller (4-30 cm tall), and has 6-12 heads in a corymb inflorescence. Ours is ssp. arida [=A. arida]. Antennaria umbrinella (umber pussytoes) is 7-16 cm tall, heads 3-8; phyllaries are whitish, yellowish, or more often pale brownish. In our area it occurs in the alpine to subalpine habitats of the San Francisco Peaks.

Synonyms: Antennaria bakeri, Antennaria sierrae-blancae

Editor: Springer et al. 2008