152 
COMPOSITE. 
ttt Receptacle without scales. Heads discoidal. 
(23.) 18. Artemisia. Florets of the disk herm., of the ray 
fern, slender in 1 row, or all herm. and tubular. Involucre 
roundish, imbricated. Receptacle naked or hairy. Fr. 
obovate, with a small epigynous disk, without pappus. 
(24.) 19- Tanacetum. Florets as in Artemisia. Involucre 
hemispherical imbricated. Receptacle naked. Fr. oblong, 
angular, with a large epigynous disk (as broad as the fruit), 
crowned with a slight membranous border. 
tttt Receptacle scaly. Pappus of 2 — 5 stiff bristles. 
(25.) 11. Bidens. Heads homogamous, discoidal, sometimes 
radiant. Florets (of the ray neuter, ligulate ;) of the disk 
herm., tubular. Receptacle flat. Involucre of 2 rows, outer 
row spreading. Branches of the style surmounted by short 
cones. Fr. compressed, angular, rough at the edges, the 
angles terminating in 2 — 5 stiff retrorsely hispid bristles. 
Suborder II. CYNAROCEPHALE^E. 
Florets all tubular forming a convex or hemispherical top. 
Stigma jointed to the style. 
* Pappus in 1 — 2 roics, not surrounded by an elevated margin. 
26. Saussurea. Florets all herm., tubular. Anth. with 
ciliated seta? at the base. Involucre imbricated, unarmed. 
Receptacle scaly. Pappus in 2 rows, outer of short rough 
bristles, inner feathery. 
27. Carlina. Florets all herm., tubular. Anthers with cili- 
ated appendages at the base. Involucre imbricated, outer 
scales lax leafy spinose, inner linear membranous coloured 
and resembling a ray. Receptacle with cleft scales. Pap- 
pus in 1 row, branched and feathery, connected into a ring 
below. 
** Pappus in many rows of different lengtlis : second row 
longest, placed within the margin which surrounds the epi- 
gynous disk, rarely 0. 
28. Centaurea. Anthers with papillose filaments, involucre 
imbricated. Receptacle chaffy. Fr. attached laterally above 
the base to the receptacle. Pappus pilose, rarely 0. 
*** Pappus in many rows not surrounded by a prominent 
margin. 
29. Arctium. Involucre globose imbricated with scales ter- 
