Senecio flaccidus

Threadleaf ragwort is a fast-growing, short-lived (3 to 6 years) bushy perennial shrub growing to tall. It is covered by a white close wool. The stems are grooved and the branches are thin, herbaceous above and woody near the base. ;Seeds: Dicotyledon fruits; each a -long achene that is ribbed and hoary, covered with short white hairs. == Taxonomy and names ==

The species was formerly recorded as Senecio douglasii (in honor of the botanist David Douglas). The name threadleaf ragwort stems from the appearance of the leaves. Other common names include: threadleaf groundsel, bush senecio, creek senecio, shrubby butterweed, comb butterweed, smooth threadleaf ragwort, Mono ragwort, Douglas ragwort, Douglas groundsel, sand wash groundsel, felty groundsel, old man, yerba cana, squawweed, and cenicillo. Subspecies • Senecio flaccidus Less. var. flaccidus • Senecio douglasii DC. var. longilobus (Benth.) L.D. Benson • Senecio douglasii DC. var. jamesii (Torr. & A. Gray) Ediger ex Correll & M.C. Johnst. • Senecio douglasii DC. ssp. longilobus (Benth.) W.A. Weber • Senecio flaccidus Less. var. monoensis (Greene) B. L. Turner & T. M. Barkley • Senecio flaccidus Less. var. douglasii (DC.) B. L. Turner & T. M. Barkley • Senecio flaccidus var. flaccidus == Distribution and habitat ==

S. flaccidus can be found from the central to the southwestern United States, overlapping with the Great Plains region. It is native between Utah and Kansas, south to Arizona, New Mexico and Texas, and much of northern and central Mexico. Like other members of its genus, it prefers disturbed habitats, especially overgrazed rangelands, dried-up streambeds and desert grasslands. It can be found at altitudes between . It is common in gravelly washes, dry creek beds, along roads and trails, and mostly away from the coast. Native :America ::North-Central U.S.: Kansas, Oklahoma ::Northwestern: Colorado ::South-Central: New Mexico, Texas ::Southwestern: Arizona, ::Northern Mexico: Chihuahua, Coahuila, Durango, San Luis Potosí, Sonora, Zacatecas ::Central Mexico: Aguascalientes, Guanajuato, Hidalgo, Jalisco (n.e.), Veracruz Current :America ::North-Central: Kansas, Oklahoma, Wyoming ::Northwestern: Colorado ::South-Central: New Mexico, Texas ::Southwestern: Arizona, California, Nevada, Utah ::Northern Mexico: Chihuahua, Coahuila, Durango, San Luis Potosí, Sonora, Zacatecas, Baja California ::Central Mexico: Aguascalientes, Baja Norte, Guanajuato, Hidalgo, Jalisco (n.e.), Veracruz == Ecology ==

Colonizing disturbed areas including over-grazed lands, S. flaccidus helps to achieve a quick groundcover and helps to stabilize the soil for longer-lived perennials. == Toxicity ==

The species is poor forage for cattle and horses due to the alkaloids contained in the plant; these cause liver disease when consumed in large quantities. as well as senecionine, seneciphylline, florosenine, otonecine-based florosenine, and retrorsine. ==See also==