152 CARDUACEAE. 



1. H. debilis Nutt. Stems 3-9 dm. long, scabrous: leaf-blades deltoid or 

 somewhat hastate to ovate-lanceolate, 4-8 cm. long, repand or shallowly 

 toothed: bracts of the involucre lanceolate or linear-lanceolate, 8-10 mm. long: 

 ligules of the ray 10-15 mm. long: disk 15-20 mm. wide. — Pinelands and sand- 

 dunes, U. S. keys, U. keys, L. keys. — [E. K.] — Sunflower. 



Jff^ 18. XIMENESIA Cav. Annual caulescent herbs. Leaves alternate or 

 sometimes opposite: blades toothed or somewhat laciniate. Heads peduncled, 

 often showy. Involucres flat, or flattish. Bracts rather narrow and elongate. 

 Ray-flowers numerous: corollas with a slender tube and yellow ligules. Disk- 

 corollas with a narrowly funnelform throat and a short tube: lobes triangular 

 or lanceolate-triangular. Filaments nearly as long as the anthers. Pappus 

 of short awns. 



(. 1. X. encelioldes Cav. Plants 3-7 dm. tall, pale-pubescent: leaf -blades deltoid 

 or lanceolate, 5-10 cm. long, serrate or incised, the broader petiole-bases 

 appendaged at the base: larger bracts of the involucre linear to linear-lanceo- 

 late, 15-20 mm. long: ligules cuneate, 1-2 cm. long: achenes 6-7 mm. long, 

 broadly winged.— Hammocks and waste places, Key West. Nat. of S. W. 

 N. Am.— {Bah., Cuba.) 



?^.' 19. COREOPSIS L. Erect or diffuse herbs. Leaves various. Heads con- 

 spicuously radiate. Involucre campanulate to hemispheric: bracts distinct or 

 nearly so, the outer ones narrow. Ray-flowers several: corollas with yellow, 

 particolored, or pink ligules. Disk-corollas with a funnelform throat and a 

 stout tube. Achenes with entire or pinnate wings, or wingless. — Tickseed. 



r 1. C. Leavenworthii T. & G. Plants 5-15 cm. tall, glabrous: blades of the 

 ■' lower leaves mostly with 2 or more narrow lobes (or broad in C. Leavenioorthii 



Garberi), those of the upper leaves mostly entire and narrow: outer involucral 



bracts subulate-lanceolate, 1-2 mm. long: achenes roundish oval, 2.5-3 mm. 



long, the wing as broad as the body. — Pinelands, L. keys. — [E. K.] — 



Coreopsis. 



,.' '20. 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. Ray-flowers 

 few and with 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. — Beggak-ticks. Bur-marigold. 



Leaf-blades 1-3-pinnately dissected, the divisions incised or lobed : ray-flowers with 



inconspicuous, entire ligules. 1- B. bipinnata. 



Leaf-blades 1-pinnate or undivided, the segments regularly serrate : 



ray-flowers with showy and lobed ligules. 2. B. leucantha. 



/^ 1. B. bipinnata L. Plants glabrous or nearly so, the stem 4-angled, branched 

 and rather slender, 3-17 dm. high: primary leaf-segments thin, deltoid, the 

 ultimate one lanceolate, incised or lobed: outer involucral bracts 7-10, linear, 

 shorter than the acute inner ones: ray-flowers few: ligules yellowish-white, 

 about equalling the disk, mostly entire: achenes fusiform, much longer than the 

 involucre, the outer slightly shorter. — Hammocks and cultivated grounds. 

 Key West. 



^- 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 



