This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Mostly perennial herbs, with scapose, often branched stems and mostly basal tufted leaves, pinnatifid to entire, those of the scapes few, scale-like, very small, or none. Heads mostly large, long-peduncled. Flowers yellow. Involucre oblong-cylindric to campanulate, its bracts herbaceous, imbricated in several series, appressed, the outer smaller. Receptacle flat, chaffy. Anthers sagittate. Style-branches slender, obtusish. Achenes oblong to linear, 10-ribbed, somewhat narrowed below, contracted above into a long or short beak, or the outer truncate. Pappus of 1 row of plumose bristles, sometimes with some shorter simple ones. [Greek, for pigs, which are fond of its roots.]
About 50 species, natives of Europe, Asia and South America. Type species: Hypochaeris glabra L.
Hypochaeris radicata L. Sp. Pl. 811. 1753.
Perennial; stems several together, glabrous, slender, 1°-2° high, bracted, or rarely simple, bearing a few scales. Leaves spreading on the ground, oblanceolate to obovate in outline, pinnatifid-lobed to dentate, 2'-6' long, hirsute on both sides; involucre oblong-cylindric, about 1' high, its bracts glabrous, or sparingly pubescent; heads 1' broad or more; chaff of the receptacle of narrow soft jointed scales; achenes rough, all with very slender beaks longer than the body; flowers longer than the involucre.
In waste places, Ontario to New York, southern New Jersey and Pennsylvania. Also in California, Oregon, Washington and Colorado. Jamaica. Adventive or naturalized from Europe. Native also of Asia. May-Oct.
Hypochaeris glabra L., the smooth cat's-ear, a smaller species, with nearly or quite glabrous leaves, flowers scarcely longer than the involucre, and the outer achenes truncate, has been found in Maine and Ontario, and in Georgia, and is naturalized on the Pacific Coast.