366 SYNANTHERE^. 



17. BACCHARIS, L. 



Heads discoid, dioecious ( ? sometimes with a few central $ ; $ with a few peripherical 

 ? flowers). Involucre imbricate. Receptacle naked. Corolla $ dilated above, ? fili- 

 form. Anthers tailless. Achenium costate: pappus pilose. — Shrubs, rarely herbs, often 

 resinous ; flowers whitish, or yellow. 



* Branches leafy, wingless ; leaves 3-triplinerved. 



70. B. speciosa, DC. Glabrous; branches cylindrical ; leaves elliptical or elliptical - 

 oblong, mucronate, tapering into a short, clasping petiole, 'h-nerved and loosely reticulated- 

 veiny, entire ; heads hemispherical, in a contracted, fastigiate corymb ; peduncles angular ; 

 involacral scales in both sexes ovate-roundish, ciliate, exterior mucronulate ; achenium gla- 

 brescent; pappus rusty, in ? uniserial.— 6'-8' high ; leaves 5"-3" long, 20"'-l 5'" broad ; 

 heads 3'" diam. — Hab. Dominica!, Imr., in the mountains; [Guadeloupe]. 



71. B. nervosa, DC! Glabrous, somewhat leprous; branches striate-subangular, 

 virgate ; leaves rigid, ovate-lanceolate or lanceolate, acuminate, acute at the base, shortly 

 petioled, ^-nerved, or slightly triplinerved, veinless above, entire; corymbs several(-few)- 

 headed, in a spreading panicle : heads hemispherical, iuvolucral scales ovate and oblong-lan- 

 ceolate, bluntish or blunt, ciliate. — Eupatorium, Sieb. Tr. 76 {non Sw.). — Habit of B. 

 rhexioides, Kth. Leaves 3"-l" long, 12"'-3'" broad; heads 2'" diam.— Hab. Trinidad!, 

 Sieb., Lockh., Cr.; [Guadeloupe; Costarica]. 



** Branches leafy, wingless ; leaves 1 -nerved. 



72. B. dioica, V. Glabrous ; branches cylindrical, angular above ; leaves leathery, ob- 

 lanceolate or obovate, bluntish, mucronulate or retuse, shortly petioled, 1-nerved, entire, 

 punctate beneath : veins inconspicuous, or 2-4 longer ones from near the base ; corymbi- 

 ferous branches nearly fastigiate : heads turbinate-cylindrical, pedicellate ; involucral scales 

 oblong-lanceolate, bluntish, glabrous, exterior ovate ; achenium glabrous : pappus pale-rusty, 

 in $ 1 -serial.— Vahl, Symb. t. 74.— B. Vahlii, DC— Leaves S'"-2i" long, 5"'-6'" broad; 

 heads 2'" long. — Hab. Bahamas!, Swains., Turk Islands!, Hjalmars.; Jamaica!, Pd., 

 M'Nab ; Montserrat ; [S. Croix, Desirade !]. 



73. B. myrsinites, Pers. Puberulous above, early glabrous; branches cylindrical, 

 angular above; leaves rigid, elliptical-lanceolate, elliptical-oblong or lanceolate, sharply 

 acuminate or cuspidate, acute at the base, shortly petioled, or subsessile, 1 -nerved, few-ser- 

 rulate or subentire, punctate beneath : veins equal, pinnate, inconspicuous above ; heads in 

 contracted corymbs, subsessile-glomerate, ovoid-cylindrical ; involucral scales ovate and 

 ovate-obloug, bluntish, ciliate, puberulous, glabrescent. — Conyza, Lam. — Leaves 2"-l" long, 

 6"'_8'" broad; heads 3'" long.— Hab. Jamaica!, Pd., M'Nab, in pastures, S. Thomas i. E.; 

 [Haiti]. 



*** Branches wingless, subaphyllous. 



74. B. scop aria, Sw. Glabrous; branch lets slender, rigid, densely approximate, 

 broom-like, tetragonal, subaphyllous, viscous ; reduced leaves distant, oblong-linear, blunt, 

 sessile, subentire, 1 -nerved, veinless ; heads small, ovoid, distant in loose, rigid corymbs, 

 long-pedicellate ; exterior involucral scales ovate, bluntish, interior ovate- lanceolate, ciliate 

 at the bluntish point ; achenium glabrous •. pappus whitish, 1 -serial. — Br. Jam. t. 34./. 4. — 

 Calea, L. ; Chrysocoma, L.; Molina, Less. — 3'-8' high, shrubby or arborescent; leaves 

 2"'-3'" long ; heads If long, whitish. — Hab. Jamaica !, all coll., on the summits of the 

 mountains, S. Andrews, Port Royal. 



18. PLUCHEA, Cass. 



Head discoid : $ flowers exterior, many -serial, subtruncate-filiform; <? central, campa- 

 nulate above, furnished with a subentire style; Involucre imbricate. Receptacle naked. 

 Anthers 2-tailed. Achenium subcylindrical : pappus pilose. — Shrubs or herbs, often fetid ; 

 heads purplish, corymbose. 



75. P. odorata, Cass. Shrubby; branches rusty -tomentose ; leaves oblong or ellip- 

 tical-oblong, pointed, quite entire, or denticulate, repand, glandular-puberulous above, hoary- 



