Helianthus annuus

 

Helianthus annuus (common sunflower) (girasol)

Asteraceae

• Stout annual; stem very hispid and rough, simple or profusely branching, 3-30 dm. tall; leaf blades 7-30 cm. long, usually broadly ovate, serrate, truncate to subcordate, rough-scabrous, green, the petiole often as long as or longer than the blade; heads single and terminal on long, stout peduncles, or the inflorescence forming an open, cymose, long-branched, long-peduncled, leafy-bracted panicle; phyllaries 1.5-2 cm. long, 5-10 mm. wide, broadly ovate, as long as or sometimes longer than the disc flowers, often conspicuously ciliate and densely hispid to hirsute, the apex abruptly narrowed and produced into a long, tail-like acumination; receptacle bracts apically 3-cleft, all 3 cusps acute, the lateral ones somewhat lacerate, the longer, lanceolate middle cusps acute, the lateral ones somewhat lacerate, the longer, lanceolate middle cusp hispid almost to its purple, acuminate, tip, about as long as the disc flowers and appressed until the later open; rays 2-4 cm. long; disc 2.5-4 cm. broad at maturity, disc flowers reddish or purplish (in wild forms); achenes 4-7 mm. long. glabrous or sparingly pubescent, variously colored and striped or speckled; pappus of 2 lanceolate paleae without intervening squamellae. Often in moist areas on valley lands, plains, or prairies. An introduced species widely distributed in the United States, but occurring only in areas disturbed by man. Domesticated forms occur in cultivation almost throughout the world. "A Flora of the Marshes of California. Herbert L. Mason".