45. COMPOSITA. 161 
B. Pappus 0, or membranous. 
+ Receptacle without scales. Heads heterogamous, radiant. 
Fi. of the ray fem., ligulate, in 1 row; of the disk herm., 
tubular. 
(16.) 6. Bexurs. Phyll. in 2 rows equal obtuse. Receptacle 
conical. Fr. compressed. Pappus 0. 
(17.) 15, CurysantHEemum. Involucre hemispherical. Fr. 
terete, without wings, or slightly angular and somewhat 
winged. Pappus 0 or of 3 minute teeth. 
(18.) 16. Marricaria. Involucre conical, hemispherical or 
nearly flat. Fr. angular, not winged. Pappus 0, or a slight 
membranous border. 
Tt Receptacle without scales. Heads discoidal. 
(19.)17. Arremista. Florets ofthe disk perfect, of the ray 
fem. slender in ] row; or all herm. and tubular. Involucre 
roundish. Phyll. imbricated. Receptacle naked or hairy. 
Fr. obovate, with a small epigynous disk, without pappus. 
(20.) 18. Tanacetrum. Florets as in Artemisia. Involucre 
hemispherical. Phyll. imbricated. Receptacle naked. Fr. 
oblong, angular, with a large epigynous disk (as broad as the 
fruit), crowned with a slight membranous border. 
ttt Receptacle scaly. Pappus 0. 
(21.) 12. Anruemis. Heads heterogamous, radiant. Florets 
of the ray fem., or neuter, ligulate, m 1 row; of the disk 
herm., tubular. Receptacle convex or conical. Phyll. im- 
bricated, of few rows. Fr. terete, or obtusely tetragonal, 
without pappus, but with a more or less prominent margin. 
[Anacycuus. Fr. compressed, winged at the edges. Other- 
wise like Anthemis.] 
(22.) 13. AcHiLLEa. Heads heterogamous, radiant. Florets 
of the ray fem., ligulate, short ; of the disk herm., tubular, 
tube plane-compressed 2-winged. Receptacle narrow, shghtly 
elevated. Involucre ovate or oblong. Phyll. imbricated. 
Fr. compressed, without pappus. 
(23.) 14. Diorrs. Heads homogamous, discoidal. Florets 
herm., tubular, tube compressed with 2 auricles at the base. 
Receptacle convex with concave downy-topped scales. Inv. 
bellshaped. Phyll. imbricated. Fr. compressed, crowned 
with the persistent auricled tube of the cor., pappus 0. 
