196 CARDUACEAE. 



3. C. longifolia Small. Plants 7-10 dm. tall: blades of the lower leaves 

 linear-oblong, linear-lanceolate, or linear, entire: outer involucral bracts lance- 

 olate, 2-4 mm. long: achenes obovate or spatulate in outline, about 4 mm. long. 

 — Everglades. 



4. C. gladiata "Walt. Plants 6-12 dm. tall: blades of the lower leaves elliptic, 

 oblong, or oblaneeolate, entire: outer involucral bracts broadly triangular, 

 3^ mm. long: achenes elliptic-oblong, about 3.5 mm. long. — Everglades. 



31. BIDENS L. Erect herbs. Leaves opposite, or the upper sometimes 

 alternate : blades entire, toothed, or divided. Heads erect or nodding. Invo- 

 lucre double, the outer bracts foliaceous, the inner appressed. Eay-flowers 

 few and ^\'ith white or yellow ligules, or wanting. Disk-corollas with a short 

 tube and a longer throat: lobes mostly deltoid. Achenes flat, terete or 4- 

 angled. Pappus of 2-4 rigid, barbed awns. — Beggar-ticks. Bur-marigold. 



Leaf-blades merely toothed: achenes flat, dilated at the top. 1. B.T^ashii. 



Leaf-blades divided : achenes slender, tetragonal, contracted at the top. 2. B. leucantha. 



1. B. Nashii Small. Plants 5-12 dm. tall, succulent: leaf -blades oblaneeolate, 

 obovate, or oblong-lanceolate, finely serrate or entire: heads erect or nodding 

 at maturity, large: involucres 9-12 mm. long: ray-flowers few; ligules oblong 

 to oblong-obovate, yellow, 1.5-3 cm. long: achenes cuneate. — Everglades. 



2. B. leucantha (L.) Willd. Plants 4-10 dm. tall, not succulent: leaf -segments 

 thick, ovate to ovate-lanceolate, mostly crenate-serrate: heads erect, small: 

 involucres 5-7 mm. long : ray-flowers few ; ligules cuneate to suborbicular, 

 white, 1-2 cm. long: achenes slender-fusiform. — Pinelands, hammocks and 

 waste places. Nat. from Trop. Am. — F. K. (Ber., Bah., Cuba, Ant.) 



32. ACTINOSPERMUM Ell. Erect herbs. Leaves alternate, often nu- 

 merous: blades very narrow, entire. Involucre hemispheric or depressed: bracts 

 lax. Eay-flowers several: corollas with rather broad yellow ligules. Disk- 

 ■corollas with a cylindric-campanulate throat and a very short or obsolete tuber 

 lobes lanceolate. Filaments shorter than the anthers. Pappus of 7-12 obovate- 

 orbicular scales. 



1. A. angustifolium (Pursh) T. & G. Plants 2-5 dm. tall: leaf-blades nar- 

 rowly linear or slightly broadened upward: heads showy: involucral bracts 

 acuminate: ray-flowers 8-10; ligules cuneate, bright-yellow, less than 2 mm. 

 long: disk-corollas 4-5 mm. long; lobes lanceolate: achenes turbinate, about 

 2 mm. long.— Pinelands. 



33. TE.IDAX 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 Ij. 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 and cultivated grounds. Nat. of Trop. Am. — F. K. 

 (Bah., Cuba, Ant.) 



