484 Supplement 



Common in Antelope Valley and extending through San Antonio 

 Pass to the vicinity of Newhall, where it was first discovered by 

 Parish. This species is closely related to A. tridentata. 



Carduus. Page 441, line 4, substitute "a single" for "sev- 

 eral." 



Silybum Mariaiium (L.) Gaertn. Page 442, insert above 

 Centaurea. Biennial herb, with very large prickly sinuate- 

 pinnatifid clasping leaves, conspicuously blotched with white; 

 heads solitary at the ends of the branches, 2.5-5 cm. broad; 

 involucral bracts broad, appressed, ending in a spreading 

 spine; corolla-tube slender, conspicuously dilated below the 

 narrowly linear lobes. 



Introduced from the Mediterranean region. Commonly called 

 Milk Thistle. 



Taraxacum officinale Weber. Page 449, insert above SoncJunt. 

 Perennial acaulescent herb, with pinnatifid or sinuate leaves, 

 and large heads of yellow flowers terminating naked hollow 

 scapes; involucral bracts of two sorts, the outer reflexed, 

 the inner erect in a single series; achenes greenish- 

 brown oblong-ovate, 4-5-ribbed, spinulose above, attenuated 

 into a long slender beak; pappus of numerous unequal simple 

 capillary bristles. 



The common Dandelion is becoming frequent in lawns. 



Taraxacum erythrosperniuni Andrz. Resembles the com- 

 mon Dandelion, being best distinguished by the red instead of 

 greenish-brown achenes. 



This species is frequent in the San Francisco Bay region, and is 

 to be expected in the lawns of southern California as well. 



