Argemone mexicana L.

  • Authority

    Acevedo-Rodríguez, Pedro & collaborators. 1996. Flora of St. John, U.S. Virgin Islands. Mem. New York Bot. Gard. 78: 1-581.

  • Family

    Papaveraceae

  • Scientific Name

    Argemone mexicana L.

  • Description

    Species Description - Erect herb, 30-60 cm tall, with a woody taproot; latex yellow-ish; stems glaucous, sparsely spiny. Leaf blades 7-25 x 2-10cm, deeply sinuate to dissected, chartaceous, glaucous underneath sparsely spiny on both surfaces, the venation whitish, the apex obtuse to acute, the base cuneate or attenuate, the margins sparsely spiny; petioles 8-10 mm long on basal leaves, the upper leaves sessile. Flowers solitary in leaf axils, sessile or nearly so, subtended by a pair of foliaceous, spiny bracts; peduncle to 3.5 cm long. Sepals free to base, ovate, green, 1.8-2.2 cm long, horned at apex, early deciduous; petals yellow, broadly obovate, 2-3 cm long; stamens numerous, the filaments yellow, 7-8 mm long, the anthers lanceolate, recurved; ovary ovoid, with soft, ascending spines, green, the stigma capitate, 5-lobed, reddish. Capsule nearly cylindrical, slightly lobed, 2.7-4 cm long, turning from green to straw-colored, dehiscing from the apex. Seeds numerous, nearly elliptic, dark brown to blackish, ornamented, ca. 2 mm long.

  • Discussion

    Common names: Mexican poppy, thistleroot, yellow-thistle

  • Distribution

    A common weed of open disturbed areas. Long Bay (A672). Also on St. Croix, St. Thomas, and Tortola; widespread weed throughout the tropics.

    Tortola Virgin Islands South America| Saint Thomas Virgin Islands of the United States South America| Saint Croix Virgin Islands of the United States South America|