COMPOSITAE 903 



Receptacle flat or nearly so; rays yellow 



9227. Coreopsis, p. 979. 



Receptacle convex to columnar. 



Involucral bracts with thin, scarious margins 



9330. Anthemis, p. 988. 



Involucral bracts distinctly herbaceous. 

 Pappus consisting of 2 flat awns. 



Awns of pappus decidedly deciduous 



9200. Helianthus, p. 970. 



Awns of pappus persistent 



9215. Actinomeris, p. 978. 



Pappus none or merely a crown of short teeth. 



Rays pistillate, rose colored (rarely yellow) 



9178B. Brauneria, p. 968. 



Rays neutral, yellow to brownish red or orange. 

 Achenes 4-sided, marginless; leaves not pinnately 



divided 9178. Rudbeckia, p. 964. 



Achenes flattened and margined; leaves pinnately 



parted 9178C. Ratibida, p. 969. 



Rays fertile, pistillate. 



Disk flowers also fertile, their achenes maturing. 

 Leaves simple; rays yellow. 



Leaves serrate 9218. Verbesina, p. 979. 



Leaves entire 9253. Madia, p. 986. 



Leaves dissected or bipinnately parted; flowers white, 

 rarely pinkish. 

 Heads (with rays expanded) more than 1 cm wide; 



achenes tuberculate, terete; annual 



9330. Anthemis, p. 988. 



Heads (with rays expanded) less than 1 cm wide; achenes 



smooth, fiat; perennial 9332. Achillea, p. 989. 



Disk flowers not fertile; mature achenes flat. 

 Rays 5, obcordate, scarcely exceeding the disk, whitish. 



9138. Parthenium, p. 959. 



Rays more than 5, yellow, much longer than the disk; 

 achenes with wide margins. . .9131. Silphium, p. 956. 



Series II. Liguliflorae DC. 



Pappus none 9556. Serinia, p. 1004. 



Pappus composed of scales or of both scales and bristles. 



Pappus of scales only; flowers blue, rose colored or white 



9553. Cichorium, p. 1004. 



Pappus composed of scales and bristles; flowers yellow 9560. Krigia, p. 1004. 



Pappus composed of either bristles or hairs. 



Bristles plumose (seen best when mature and dry). 



Plants scapose 9572. HYPOCH AERIS, p. 1006. 



Plants not scapose 9579. Tragopogon, p. 1006. 



Bristles simple, at most scabrous. 



Achenes spinulose at the summit 9592. Taraxacum, p. 1006. 



Achenes not spinulose at the summit. 

 Achenes flat or flattish. 



Achenes beaked; flowers light yellow 9596. Lactuca, p. 1008. 



Achenes narrowed at the apex or truncate. 



Flowers blue (rarely cream color in Lactuca spicata) 



9596. Lactuca, p. 1008. 



Flowers yellow 9595. Sonchus, p. 1007. 



