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..
Senecio integerrimus Nutt. Gen. 2: 165. 1818.
Perennial, more or less pubescent when young, glabrous or nearly so when old; stem stout, 1°-4° high. Leaves entire, or sparingly denticulate, somewhat fleshy, the lower and basal ones oval or oblong, obtuse or obtusish at the apex, 3'-8' long, 1'-1 1/2' wide, petioled, the upper linear or lanceolate, acute, the uppermost very small; heads numerous, corymbose, long-peduncled, 6"-10" broad; involucre nearly cylindric, 4"-5" high, its principal bracts linear, acuminate, green, usually with a few subulate outer ones; rays 8-12, linear-oblong; achenes nearly glabrous; pappus white.
Iowa and Minnesota to Manitoba, Saskatchewan and Wyoming. June-July.
Senecio lugens Richards., of northwestern North America, admitted in our first edition, is not definitely known to occur within our area.