XLII1. COMPOSITE. 249 



are but few in Europe, confined to mountain regions or high northern 

 latitudes. 



1. S. alpina, DC. (fig. 557). Alpme S. Stem erect and simple 

 seldom a foot high, covered, as well as the involucre and under side* 

 of the leaves, with a loose cotton, which wears off with age. Leaves 

 from ovate to lanceolate, entire or toothed, 2 to 3 inches long. Flower 

 heads ovoid or oblong, nearly sessile, in a small, dense terminal corymb, 

 with purple florets. The soft, feathery pappus projects beyond the 

 involucres, the inner bracts of which are softly hairy. 



In high northern latitudes, or at considerable elevations in the 

 mountain -ranges of Europe, Russian Asia, and Arctic America. Fre- 

 quent in the mountains of Scotland, and found also in North Wales, in 

 the Lake district of northern England, and in West Donegal, Ireland. 



XXV. CARDUUS. THISTLE. 



Herbs, with hard stems. Leaves often cut, and usually very prickly. 

 Involucres globular or ovoid, the bracts numerous, closely imbricated, 

 and usually prickly. Receptacle thick, bearing bristles between the 

 florets. Florets all equal and tubular. Achenes glabrous, with a pappus 

 of numerous simple or feathery hairs longer than the achene itself. 



The largest and widest-spread genus among Cynaroidece, for although 

 the species are chiefly European and Asiatic, yet there are also several 

 from North America, and the common ones accommodate themselves 

 readily even to a tropical climate. They are usually divided into two 

 genera, Cnicus (Cirsium of some authors) with a feathery pappus, and 

 Carduus proper with a simple-haired pappus ; but the distinction is so 

 purely artificial that several botanists now revert to the old natural 

 limits indicated by Linnasus. 



Pappus consisting of simple hairs (CARDUUS proper). 

 Bracts of the large involucre very broad at the base, with 



lateral as well as terminal prickles 1. C. Marianus. 



Bracts of the involucre lanceolate or linear, without lateral 

 prickles. Involucres globular, large. 



Involucral bracts broadly lanceolate- 2. C. nutans. 



Involucral bracts linear . . . . ' . . . 8. C. aca.nthoid.es. 



Involucres ovoid or cylindrical 4. C. pycnocephului. 



Pappus consisting of feathery hairs (CNicus). 

 Leaves decurrent along the stem, forming prickly wings. 

 Flower-heads all peduncled. 

 Flower-heads few, near 1J inches long. Stem winged 



and prickly. Root biennial 5. C. lanceolatus. 



Flower-heads not *n inch long, in terminal corymbs. 



Leaves but little decurrent. Rootstock creeping. 7. C. arvensis. 

 Flower-heads small in dense clusters. Stem winged and 



prickly .... 6. C. palustrit. 



leaves not decurrent, or only very thortly so. 

 Flower-heads sessile or on very short peduncles. 

 Stems stout and branched (about 2 feet). Involucres 



large and cottony 8. C. eriophortu. 



Stems dwarf, or scarcely any. Involucres not cottony . 12. C. acauli*. 

 Flower-heads all peduncled. Rootstock perennial, often 

 creeping. 



Flower-heads in terminal corymbs 7. C. arveruii. 



Flower-heads growing singly on long peduncles. 



