166 KEY AND FLOE A 



a. M. Courteri Gray. Erect, with glaucous stems and leaves. 

 The bracts of the involucre are broad, blunt, shining, and papery, with a 

 green midrib, loosely arranged in several rows ; the flowers are white, 

 turning pink in drying or fading. This is one of the most notice- 

 able annuals of the San Joaquin Valley. 



b. M. Calif or' nica DC. Annual, with the heads large, solitary at the 

 ends of scape-like stems, the leaves all radical and pinnately parted 

 into narrow, linear divisions. Flowers yellow. The scales of the 

 involucre are linear and loosely ranked. Pappus of 2 persistent 

 bristles and minute-pointed teeth between. This generally grows 

 in sandy soil, and is most common in southern California. 



c. M. saxa'tilis T. & G. Perennial, with leafy, branching stems, 

 1-4 ft. high. Leaves entire or cut into slender divisions from lan- 

 ceolate to thread-like, in some varieties quite fleshy. Heads many- 

 flowered, an inch or less in diameter, terminating the branchlets, 

 white turning to rose-color. Involucres of numerous, narrow bracts 

 extending down onto the peduncle. Akenes ribbed, the summit 

 with a border of minute white teeth. This is common in southern 

 California, blooming in summer and fall, and in several varieties 

 from the seacoast to the higher hills. 



VIII. TROX1MON, Western Dandelion 



Perennial herbs, with radical leaves and heads of yellow 

 flowers on hollow scapes. Akenes with smooth ribs and a long 

 beak ; the bristles of the capillary pappus falling singly. The 

 involucre consists of bracts in several series. 



IX. TARAX'ACUM, Dandelion 



Similar to Troximon. The akenes have a long beak and the 

 bristles of the pappus persist on the akene. The only species 

 is not native. 



X. SON'CHUS, Sow Thistle 



Herbs with spiny leaves, and erect, branching stems. Heads 

 with the bracts in several series, and flowers yellow. Akenes 

 flat, with soft, silky-white, capillary pappus. 



a. S. olera'ceus L. Leaves pinnatifid, tipped with soft spiny 

 teeth, tapering from an auricled base to a long point, the auricles 

 acute, akenes rough. This is a very common introduced weed. 



