broom snakeweed, more...
[Gutierrezia divaricata (Nutt.) Torr. & A. Gray, more]
10-60(-100) cm. Stems
minutely hispidulous. Leaves:
basal and proximal absent at flowering; cauline blades 1- or 3-nerved, linear to lanceolate, sometimes filiform and fascicled, 1.5-2(-3) mm wide, little reduced distally. Heads
(sessile to subsessile in compact glomerules) in dense, flat-topped, corymbiform arrays. Involucres
cylindric to cuneate-campanulate, 1.5-2(-3) mm diam. Phyllary apices
flat. Ray florets
(2-)3-8; corollas yellow, 3-5.5 mm. Disc florets
(2-)3-9 (usually bisexual and fertile, rarely functionally staminate, corollas tubular-funnelform, lobes erect to spreading or recurved, deltate). Cypselae
0.8-1.6(-2.2) mm, faces without oil cavities, densely strigoso-sericeous; pappi
of 1-2 series of narrowly oblong- to ovate-lanceolate or obovate scales (readily falling, those of discs 1
/ 3 - 1
/ 2 corollas, shorter on rays). 2n
= 8, 16, 32. Flowering Jul-Nov(-Jan). Grasslands, commonly on rocky, open slopes; 50-2900 m; Alta., Man., Sask.; Ariz., Calif., Colo., Idaho, Kans., Minn., Mont., Nebr., Nev., N.Mex., N.Y., N.Dak., Okla., Oreg., S.Dak., Tex., Utah, Wash., Wyo.; Mexico (Baja California, Baja California Sur, Chihuahua, Coahuila, Durango, Nuevo León, San Luis Potosí, Sonora, Zacatecas). Gutierrezia sarothrae
is often abundant in overgrazed pastures; it is naturalized in New York.
Plant: Subshrub 1-6 dm; stems sprawling or upright, brown below, green or tan above Leaves: alternate, sometimes in axillary clusters, entire, gland-dotted, sometimes gummy, glabrous or minutely scabrous, dark gray-green, lance-linear if single, thread-like if clustered INFLORESCENCE: primary inflorescence a head, each resembling a flower; heads 6-14-flowered, in clusters of 5 or fewer, on peduncles < 1.5 mm or sometimes sessile; involucre generally < or = 4.5 mm, < or = 2.5 mm diam, narrowly obconic; phyllaries 8-21 in 2-3 series Flowers: Ray flowers 2-8; corollas 3-5.4 mm, yellow; Disk flowers 2-9, fertile; corollas 2.3-3.5 mm, yellow, club- or narrowly funnel-shaped, lobes short, recurved; style appendages lanceolate Fruit: 0.9-1.6 mm, narrowly obconic, light tan, hairy; hairs appressed, white; pappus of 1-2 series of finely toothed, white or yellowish scales Misc: Grasslands, deserts, montane areas; 50-2900 m.; May-Oct References: J.C. Hickman, ed. The Jepson Manual.L. Benson & R. Darrow. Trees and Shrubs of the Southwestern Deserts. W.B. McDougal. Seed plants of Northern Arizona. ASU specimens.