1. Picris hieracioides L. ssp. hieracioides (hawkweed ox-tongue, cat’s ear)

Pl. 260 l, m; Map 1088

Plants biennial or short-lived perennials, with a fascicle of several slightly thickened main roots. Stems 20–80 cm long, moderately to densely pubescent with spreading, barb-tipped hairs, also sparsely to moderately pubescent with minute, appressed, sometimes cobwebby, branched hairs toward the tip. Basal and lower stem leaves 4–25 cm long, moderately pubescent with spreading, barb-tipped hairs, usually also sparsely to moderately pubescent with minute, appressed, branched hairs. Involucre 8–15 mm long, the inner series of bracts relatively flat, thin, papery to herbaceous, not becoming wrapped around the outer series of fruits, pubescent with a central band of spreading, barb-tipped hairs, usually also pubescent with sparse to moderate, minute, appressed, cobwebby, branched hairs. Corollas 1.2–2.0 cm long. Pappus 5–7 mm long. Fruits 3–5 mm long. 2n=10. July–September.

Introduced, known thus far only from the city of St. Louis (native of Europe, Africa; introduced). Railroads.

This species was first reported for Missouri by Mühlenbach (1979), based on his botanical inventories of the St. Louis railyards. In Europe, several subspecies have been segregated based on minor differences in involucre size and color, as well as inflorescence shape (Chater, 1976). The application of these names to North American nonnative populations has by no means been firmly established, but the single collection from Missouri to date appears to correspond to ssp. hieracioides.