CARDUACEAE. 153 



waste places, U. S. keys, U. keys, L. keys, L. S. keys. Nat. of Trop. Am. 

 [E. K.] (Ber., Bah., Cuba, Ant.) 



21. COSMOS Cav. Annual or perennial herbs. Leaves opposite: blades 

 entire, lobed, or 2-3-pinnately dissected. Heads peduncled, showy. Involucres 

 nearly hemispheric: bracts unequal, the outer sometimes smaller than the inner. 

 Ray-flowers few: corollas with pink, purple, or rarely orange-yellow ligules. 

 Disk-corollas with a funnelform throat and a shorter tube. Filaments as long 

 as the anthers or nearly so, sometimes pubescent. Achenes beaked. Pappus 

 of 2-4 barbed awns, or a crown. 



1. C. caudatus H.B.K. Stems 7-14 dm. tall: leaf -blades 2-pinnately parted, 

 the segments lanceolate or linear: involucral bracts linear or nearly so: ray- 

 flowers 7-12; ligules rose-colored, 1-2 cm. long: achenes fusiform, about 2 

 cm. long, the beak nearly or quite as long as the body. Waste places and cul- 

 tivated grounds, Key West. Nat. of Trop. Am. (Cuba, Ant.) COSMOS. 



22. TRIDAX L. Decumbent herbs. Leaves opposite: blades incised- 

 toothed or pinnately dissected. Heads radiate. Involucre ovoid to campanu- 

 late: bracts various, the inner broader than the outer. Ray-flowers few: 

 corollas with a slender glabrous tube and a broad yellow or pale ligule. Disk- 

 corollas with a narrowly funnelform throat and a short tube. Anthers linear. 

 Achenes much shorter than the corollas. Pappus of numerous plumose-ciliate 

 scales. 



1. T. procumbens L. Plants branched at the base, the branches hirsute: leaf- 

 blades ovate to ovate-lanceolate, 2-5 cm. long, incised or incised-lobed : invo- 

 lucres 6-7 mm. high; bracts hispidulous, the outer lanceolate, the inner broad 

 and abruptly pointed: ligules as broad as long: achenes of the disk about 2 

 mm. long. Pinelands, hammocks, and cultivated grounds, L. keys. Nat. of 

 Trop. Am. [E. K.] (Bah., Cuba, Ant.) 



23. FLAVERIA Juss. Low branched or diffuse herbs or partially woody 

 plants. Leaves opposite: blades entire or toothed. Heads small, radiate or 

 discoid, usually clustered. Involucres narrow, 1-several-flowered : bracts few, 

 often 2-5, equal or nearly so. Receptacle naked. Ray-flowers usually solitary, 

 pistillate, fruit-producing, the ligules yellow, or wanting. Disk-flowers 1-15, 

 perfect, fruit-producing: corollas yellow or yellowish, with a short throat and 

 a longer tube: lobes deltoid or triangular. Filaments mostly shorter than the 

 anthers. Achenes narrow, 8-10-ribbed. Pappus wanting. 



1. F. linearis Lag. Stem 2-9 dm. long, the branches often decumbent, corym- 

 bose above: leaf -blades narrowly linear to narrowly linear-lanceolate, 3-10 

 cm. long, entire: heads numerous: involucres about 4 mm. high; bracts mostly 

 5, oblong to lanceolate: ligules 2-3.5 mm. long: achenes about 1.5 mm. long. 

 Low pinelands and hammocks, and sandy shores, U. S. keys, U. keys, L. 

 keys, L. S. keys. [E. K.~\(Bah., Cuba, Ant.) 



24. PECTIS L. Slender or wiry glandular-dotted herbs. Leaves oppo- 

 site: blades narrow, usually ciliate near the base. Heads cymose. Involucre 

 narrow, few-several-flowered : bracts distinct, gland-bearing. Ray-flowers few : 

 corollas with yellow ligules. Styles pubescent. Stigmas of the disk-flowers 

 very short. 



1. P. leptocephala (Cass.) Urban. Stems or branches 8-40 cm. long, nearly 

 glabrous : leaf -blades narrowly linear, 1-3 cm. long : involucre 1-1.5 mm. thick : 



