Arnoseris minima (L.) Schweigg. & Korte

Plant 5–30 dm, glabrous or minutely granular-hairy; basal lvs oblanceolate or broader, mostly toothed, 0.5–7 cm × 2–15 mm; peduncles conspicuously inflated for some distance below the heads; invol 4–7 mm, its 10–22 bracts narrow; achenes 1.5–2 mm, often slightly rugose as well as strongly ribbed, otherwise glabrous, shining; 2n=18. Fields and waste places; native of Europe, but found occasionally from N.S., N.B., and Me. to Pa., O., and Mich., perhaps not becoming fully established. June–Sept.