1. Senecio ampullaceus Hook. (Texas groundsel)

Pl. 299 c, d; Map 1258

Plants with thin, fibrous roots. Stems 20–70 cm long, when young with patches of fine, woolly (cobwebby) hairs, usually becoming glabrous or nearly so with age. Basal and lower leaves 3–10 cm long, the blades narrowly ovate, unlobed, bluntly to sharply pointed at the tip, tapered at the base to a poorly defined petiole, the margins otherwise shallowly toothed to nearly entire, moderately to densely pubescent with cobwebby hairs, often becoming glabrous or nearly so at maturity. Upper leaves sessile, narrowly ovate to narrowly lanceolate-triangular, unlobed, the margins shallowly toothed to nearly entire. Heads mostly erect or ascending. Involucre 7–11 mm long, the inner bracts 11–14, uniformly green, the outer series extending down the stalk, linear, uniformly green. Disc corollas 7–10 mm long. Ray florets mostly 8, the corolla lobe 11–17 mm long, the tip rounded, entire, minutely notched, or minutely 3-toothed at the tip. Fruits 2–3 mm long. April–May.

Introduced, known only from St. Louis (endemic to Texas). Railroads.