Spring Flora of Oklahoma 
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honeycombed. Flowers all alike, perfect. Calyx-tube 
completely adnate to the ovary, its limb (pappus) of 
scales, or simple or plumose bristles, or both, or wanting. 
Corolla gamopetalous, with a short or long tube, and a 
strap-shaped, usually 5-toothed limb (ray). Anthers con¬ 
nate into a tube around the style. Ovary 1-celled. Fruit 
an achene. 
Pappus of scales, or of scales and bristles, or none. 
Pappus none; achenes 8-10-ribbed. I. Serinia. 
Pappus of rounded scales, with or without an inner 
series of bristles. 
Bracts of the involucre 9-18, reflexed in fruit, not 
keeled; pappus-bristles usually more numer¬ 
ous than the scales. 
Annuals; pappus-scales 5, obovate or rounded. 
II. Krigia. 
Perennials; pappus-scales 10-15, linear or oblong, 
minute. III. Cynthia. 
Bracts of the involucre 5-8, erect in fruit, keeled; 
pappus-bristles and scales 5. IV. Cymbia. 
Pappus, at least some of it, of plumose bristles. 
V. Tragopogon. 
Pappus, of simple bristles or of some soft white scales. 
Achenes spinulose, or with short processes near the 
summit. VI. Leontodon. 
Achenes smooth, or papillose, not spinulose toward 
the summit. 
Achenes flattened. VII. Sonchus. 
Achenes cylindric, or prismatic. 
Pappus-bristles not surrounded by villous ring at 
base. VIII. Agoseris. 
