452 COMPOSITiE. Saussurea. 



CONSPECTUS OF THE SUBTRIBES AND GENERA. 



Subtribe 1. Carlines;. — Heads discoid, homogamous. Anthers caudate. Pappus 

 mostly plumose. 



168. Saussurea. Pappus double ; the few bristles of the exterior denticulate. 



Subtribe 2. Centauries. — Heads discoid; the marginal flowers mostly neutral, 

 usually much larger than the others. Pappus never plumose, sometimes 

 wanting. 



169. Centaurea. Achenia compressed. Pappus of filiform bristles, or none. 



170. Cnicus. Achenia terete, strongly striate. Pappus triple, the exterior 



10-toothed, the intermediate of 10 long bristles, the inner of 10 short 

 bristles. Marginal sterile flowers small. 



Subtribe 3. Carduines. — Heads discoid, homogamous, sometimes dioecious. An- 

 thers slightly or not at all caudate. Pappus of plumose or scabrous bristles. 



171. CiRsiuM. Achenia smooth. Pappus plumose. Receptacle bristly. 



172. Carduus. Achenia smooth. Pappus scabrous. Receptacle bristly. 



173. Onopordon. Achenia rugose, 4-angled. Pappus barbellulatfe, united at 



the base into a corneous ring. Receptacle alveolate. 



174. Lappa. Achenia rugose. Pappus scabrous, caducous. Receptacle setose- 



fimbrillate. Scales of the involucre subulate, uncinate at the apex. 



Cynara Scolymus, Linn, (the Artichoke) is said by Nuttall {Gen. p. 129) to be 

 Bomewhat naturalized in some parts of Virginia. 



Subtribe 1. Carline.e, Cass. — Heads discoid, many-flowered, homoga- 

 mous, never dioecious. Scales of the involucre in several series, often spi- 

 nose. Anthers caudate ; the tails hairy. Pappus usually plumose. 



168. SAUSSUREA. DC. inann. mus. 16. p. 107, Sfprodr. 6. p. 531. 



Heads many-flowered ; the flowers all tubular, similar and perfect. Scales 

 of the involucre imbricated in several series, mostly not appendiculate. Re- 

 ceptacle flat, fimbrillate, or with persistent chaff". Corolla with a slender 

 tube and a 5-cleft limb ; the throat inflated. Anthers with setiform ciliate or 

 villous tails. Achenia glabrous. Pappus double ; the exterior of a few 

 short and denticulate rigid bristles ; the interior of a series of stout plumose 

 bristles, which are slightly united at the base. — Herbs (natives of the colder 

 regions of the northern hemisphere) ; with alternate leaves, and usually co- 

 rymbose heads. Corolla purple or dark violet. 



1. S. alpina (DC.) : leaves flat, nearly glabrous above, villous-tomentose 

 beneath; the lower ovate-lanceolate and somewhat toothed; the upper 

 oblong-lanceolate and entire ; heads few in a close corymb; scales of the cy- 

 lindraceous involucre appressed, villous, unarmed ; the exterior shorter. 

 DC! Ic.—Ledeb. ic. Alt. 1. t. 18; Hook.! fl. Bor.-Am. 1. p. 303. 



