Senecio ampullaceus also known as Texas ragwort1, Texas squaw-weed, Texas groundsel,3 and Texas butterweed4 is a species of Senecio in the family Asteraceae and gets its latin name ampullaceus from its flask shaped flower-head5 and is a recommended native for landscape use in Texas where it came from.6
The seedlings of S. ampullaceus often have a purplish color on the undersides of their leaves in the winter, especially along their midrib.3 Flowering in early–mid spring,7 Texas ragwort is a tall annual,8 growing to from 20 centimeters (7.9 in) to 80 centimeters (31 in) tall and similar to S. quaylei.7
Stems and leaves: The leaves with broadly winged leaf stalks, grow from single stems; the nodes between leaves getting shorter and shorter higher on the stem. Ovate leaves with pointed tips 3 centimeters (1.2 in) to 10 centimeters (3.9 in) long by 1.5 centimeters (0.59 in) to 4 centimeters (1.6 in) wide with tapered bases. Leaves at the lower portion of the plant have more teeth on their edges than the leaves at the upper portion of the mature plant.7
Stems and leaves are covered loosely and unevenly with a mat of fine hairs, occasionally having no hairs.7
Flowers: Flowering stalks have 10 to 30 flower heads which as a group make a flat top to the whole plant. Each flower head is surrounded by 2 to 8 bractlets or mini-leaves, each 1 millimeter (0.039 in) to more than 2 millimeters (0.079 in). Approximately 13 green to grayish bracts, 7 millimeters (0.28 in) to 10 millimeters (0.39 in) long surrounding 8 ray florets and an 8 millimeters (0.31 in) to 10 millimeters (0.39 in) corolla.7
^ University of Texas at Austin. "Senecio ampullaceus" (HTML). Image Archive of Central Texas Plants. University of Texas at Austin. Retrieved on 2008-04-08.