This is one of the largest families of flowering plants whose members are dis- 

 tributed over much of the earth. They consist of about 900 genera and 13,000 

 species, or about 10% of the total of flowering plants. 



Key to Tribes of the Compositae 



1. Corollas all of type "d" described above X. Cichorieae, p. 1592 



1. Corollas not of type "d" (2) 



2(1). Anthers with elongate cartilaginous mostly connate appendages at the tip 

 and caudate-appendaged basally; receptacle hairy-bristly or naked 

 IX. Cynareae, p. 1592 



2. Plants not with combination of characters given above, occasionally with 



caudate anthers or with hairy receptacle but not both (3) 



3(2). Anthers caudate-appendaged basally (i.e., with slender tail-like appendages 

 hanging from the thecae between the filaments); ray flowers (type 

 "b" corollas) absent IV. Inuleae, p. 1590 



3. Anthers not caudate-appendaged basally (in some genera such as in Tribe 



Vernonieae the anthers narrowly sagittate basally and simulating 

 caudation); rays often present (4) 



4(3). Corollas all of type "a" described above, usually white, red or purple or 

 blue, never yellow (see also Marshallia); stigmatic lines obscure, 

 present (if at all) only below the middle of the style branch (5) 



4. Corollas either of type "a" or some of type "b", often yeUow; stigmatic lines 



otherwise than above (6) 



5(4). Style branches long, slender, terete, threadlike, minutely hairy all over; 

 leaves alternate, scattered or basal I. Vernonieae, p. 1588 



5. Style branches thickened upward or clavate, obtuse, very minutely and uni- 



formly pubescent or nearly glabrous; leaves opposite, whorled or 

 alternate II. Eupatorieae, p. 1589 



6(5). Style branches of the perfect flowers flattened and smooth, extended into 

 lanceolate or elongate-deltoid hairy appendages; those flowers with 

 type "a" corollas mostly yellow; receptacle essentially naked (except 

 in Xanthisma) III. Astereae, p. 1589 



6. Style branches of the flowers with type "a" corolla not appendaged or with 



a very short or slender appendage, or else the type "a" corolla 

 not yellow (7) 



7(6). Pappus of soft very fine (capillary) bristles; involucre herbaceous, little 

 or not at all imbricated (i.e., phyllaries equal in length); receptacle 



naked; stem leaves when present mostly alternate 



VIII. Senecioneae, p. 1592 



7. Pappus absent or of scales and/ or awns and/or bristles (but when of bristles 



these not extremely fine and soft); involucre diverse; receptacle 

 naked or not; lowermost stem leaves often opposite (8) 



8(7). Phyllaries mostly scarious or papery; pappus absent; style branch tips 

 truncate; leaves alternate VII. Anthemideae, p. 1591 



8. Phyllaries or at least some of them mostly herbaceous or membranous (occa- 



sionally with hyaline marginal zones) (9) 



9(8). Receptacle chaffy (merely with awns or bristles in Eclipta) 



V. Heliantheae, p. 1590 



9. Receptable naked or merely with persistent awns VI. Helenieae, p. 1591 



/. Key to Genera of Vernonieae 



Pappus of numerous coarse bristles 1. Vernonia, p. 1592 



1588 



