142 



FAM. 173. 



ter consisting of long hair- like bristles in 1-2 series; flowers white, 



Baccharis 



B. halimifolia. Leaves numerous, suborbicular to linear-elliptic; heads numer- 

 ous in peduncled clusters of 3-5. Along the coast. Summer and Fall. 



B. glomeruliflora. Leaves rather few, spatulate to cuneate-obovate; heads 

 solitary and sessile, or few in nearly sessile clusters. About pine-land 

 swamps. Fall and winter. 



B. angustifolia. Leaves numerous, linear; heads numerous or few in pedun- 



cled clusters, or solitary on short peduncles. Brackish marshes. Fall. 



3. Flowers yellow; — rigid herbs with alternate leaves and small heads 

 often in corymbs; bracts in several rows; receptacle flat, some- 

 times with teeth around the depressions; pappus of 1-2 series 

 of rigid hair-like bristles. In pine-land. Summer. 



Chondrophora (Bigelovia) 



C. nudata. Stems mostly simple, wand-like; leaves mainly basal, spatulate- 



lanceolate, the stem-leaves scattered, linear. 



C. virgata. Similar to preceding; lowest leaves linear-spatulate, the stem-lea- 

 ves filiform; heads larger. 



3. Flowers white, blue or purple, -._____ -4 



4. Receptacle chaffy, --____.__ _ 5 

 4. Receptacle bristly; leaves spine-tipped; — herbs with sessile or de- 

 current, alternate or basal, toothed, lobed or pinnatifid leaves; in- 

 volucre of many rows mostly spine-tipped; receptacle flat or 



convex; pappus of plumose bristles, - - Carduus (Cirsium), Thistle 

 C. repandus (C. repandum). Stem very leafy, the leaves spreading; narrow- 

 oblong in outline, pinnately- lobed; plant webby; flowers purple. Dry 

 pine-land. Spring to Fall. 

 C. muticus (C. muticum). Stem tall, branching; leaves numerous, deeply 1-2 

 pinnatifid, the lobes lanceolate, spiny; bracts of the involucre woolly, cus- 

 pidate or with recurved tips; flowers purple. Low thickets. Late Summer 

 and Fall. 

 C. spinosissimus (C. horridulum). Stem woolly; lower leaves spatulate in out- 

 line, twice pinnatifid; the upper ones oblong to lanceolate in outline, often 

 pinnatifid; heads surrounded by a whorl of spiny bracts; flowers mostly 

 purple (var. Elliottii) , or yellowish. Sandy soil. Spring and Summer. 



4. Receptacle naked, ----------- 6 



5. Leaves opposite; flowers white; — rough herbs with 3-4 angled stems 



and peduncled heads; bracts in 2-3 rows; pappus of 2-several 



caducous awns, ________ Melanthera 



M. nivea (hastata). Stems blotched with purple; leaves hastately-lobed, ser- 

 rate; bracts of involucre scale-like. Light soil. Spring and Summer. 



5. Leaves alternate; flowers purple; — erect herbs with showy heads in 



terminal corymbose cymes; bracts in several rows, appressed; 

 pappus of plumose or barbed hair-like bristles. - - - Carphephorus 

 C. corymbosus. Stem tall and like the leaves pubescent; lower leaves spatu- 

 late to oblong, upper ones much smaller and sessile; heads numerous, bracts 

 of involucre scarious-margined. Sandy pine-land. Summer and FalL 



6. Bracts of the involucre in one row; — stems corymbosely branched; 



leaves alternate; heads corymbose; bracts about 5, but often 

 accompanied by a few small ones at the base; pappus copious, 



