CARDUACEAE. 453 



1. Salmea petrobioides Griseb. Fl. Br. W. I. 375. 1861. 



A inueli-branched shrub, 2 m. high or less, the twigs slender, erect-ascend- 

 ing, glabrous. Leaves obovate or ellii3tic-obovate, '2-5 em. long, 8-25 mm. 

 wide, rounded or apiculate at the apex, narrowed or cuneate at the base, fleshy, 

 the midvein prominent, the lateral veins obscure, the petioles 1.5-3 mm. long; 

 heads numerous; in terminal compound, nearly flat-topped corymbs ; involucre 

 glutinous, narrowly campanulate, about 4 mm. high^ its bracts in 2 series, 

 oblong to oval, obtuse, the outer much smaller than the inner; receptacle 

 acute; achenes oblong, glabrous except at the apex. 



Coastal rocks, white-lands, sand-dunes and coppices, throughout the archipelago 

 from Abaco. Great Bahama and the Biminis to Cat Island, Long Island and Grand 

 Caicos : — Cuban Cays ; Cayman Islands. Bushy Salmea. Shanks. Catesby, 1 : pi. 72. 



26. BIDENS L. Sp. PI. 831. 1753. 



Annual or perennial herbs, with opposite serrate lobed divided or dis- 

 sected leaves, or the uppermost alternate, and mostly large heads of both 

 tubular and radiate flowers, or the rays none, or rudimentary. Involucre cam- 

 panulate or hemispheric, its bracts in 2 series, distinct or slightly united at the 

 base; the outer often foliaceous and much larger than the inner. Eeceptacle 

 flat or nearly sO; chaffy, the chaff subtending the disk-flowers. Rays, when 

 present, neutral, mostly entire, yellow in our species. Disk-flowers perfect, 

 fertile, their corollas tubular, o-toothed. Anthers entire^ or minutely sagit- 

 tate at the base. Style-branches with short or subulate tips. Achenes flat, 

 quadrangular or nearly terete, cuneate, oblong, or linear. Pappus of 2-6 teeth 

 or subulate awns, upwardly or downwardly barbed or hispid. [Latin, two- 

 toothed, referring to the achenes.] About 75 species of wide geographic dis- 

 tribution. Type species: Bidens tripartitus L. 



Achenes 4-awned ; rays yellow, small; leaves pinnatisect. 1. B. cynapiifoUa. 



Achenes 2-awned ; rays .white or none ; leaves 3-5 pinnately di- 

 vided. . 2. B. pilosa. 



1. Bidens cynapiifolia H.B.K. Nov. Gen. 4: 235. 1820. 



Annual; stem quadrangular, erect, branched, 0.2-2 m. high. Leaves thin, 

 petioled, 1-3-pinnately dissected into ovate or oblong, toothed or lobed seg- 

 ments; heads usually numerous^ long-peduncled, 4-8 mm. broad; involucre 

 narrow, its outer bracts linear_, ascending, nearly as long as the broader erect 

 inner ones; rays 3-4, yellow, short, sometimes none; achenes curved, linear, 

 4-angled, narrowed upward, 7-17 mm. long, the outer ones commonly shorter 

 than the inner ; pappus of 4-6 downwardly barbed, slightly spreading awns, 

 much shorter than the achene. 



Waste and cultivated grounds. New Providence and Eleuthera : — West Indies ; 

 continental tropical America. Recorded by Dolley and by Hitchcock as B. hipinnata 

 L., which it resembles. Beggar-ticks. 



2. Bidens pilosa L. Sp. PL 832. 1753. 



Coreopsis leucantha L. Sp. PI. ed. 2, 1282. 1763. 

 Bidens leucantha Willd. Sp. PI. 3: 1719. 1804. 



Annual, glabrous or somewhat pubescent, 3-10 dm. high, more or less 

 branched. Leaves petioled, 3-divided, their segments ovate to lanceolate, 2-8 

 cm. long, serrate, acute or acuminate, the uppermost sometimes undivided; 

 involucre campanulate, about 8 mm. high, its outer bracts linear-oblong, usually 



