Gutierrezia sarothrae (Pursh) Britt. & Rusby  
Family: Asteraceae
broom snakeweed,  more...
[Gutierrezia divaricata (Nutt.) Torr. & A. Gray,  more]
Gutierrezia sarothrae image
Max Licher  
Subshrubs, 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.
Gutierrezia sarothrae image
Max Licher  
Gutierrezia sarothrae image
Max Licher  
Gutierrezia sarothrae image
Max Licher  
Gutierrezia sarothrae image
Max Licher  
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