358 PROCEEDINGS OF THE ACADEMY OF " [1892. 



margins: segments of the whitish or junkish corolla about as long 

 as the throat. 



Abundant in low, grassy, and occasionally inundated river bot- 

 toms of the lower San Joaquin, near Lathrop, California. A very 

 well marked and probably rather local species, flowering in May. 

 Carduus callilepis. 



Stem and leaves unknown : head pedunculate, depressed-globose, 

 barely an inch high : bracts of the involucre in many series and 

 closely imbricated, the outer broadly obovate, all except the inner- 

 most exposing round-ovoid tips with deeply lacerate scarious or 

 semi-cartilaginous margins and an abrupt short rigid erect terminal 

 spine; the veiy innermost with lanceolate scarious-margined and 

 fimbrillate tips : flowers small, ochroleucous, the limb of the corolla 

 only a third as long as the throat. 



Western California ; probably Humboldt Co., the material very 

 scanty, but indicating a very pronounced and remarkable species, 

 with involucre more like that of a Ceutaurea than of any other 

 known Carduus. 



Carduus hydrophilus. 



Rather slender and freely branching, 4 or 5 feet high ; herbage 

 Avhen young, pale with a fine and close arachnoid tomentum, in 

 maturity green and glabrate : leaves deeply pinnatifid into uniform 

 3-lobed segments: heads, numerous, little more than an inch high, 

 glomerate in twos and threes at the ends of the numerous and pan- 

 iculate Avidely spreading branchlets: involucre ovate, the somewhat 

 appressed-imbricate scales pluriserial, rather firm, with a green and 

 glutinous ridge toward the summit, and ending in a short, slender, 

 erect or slightly spreading spine : corollas deep rose-purple, the limb 

 about equalling the throat : pappus bristles very delicately and 

 sparsely long-plumose below, naked at the aristiform or clavellate 

 tips. 



Very common in the brackish marshes of Suisun Bay, California, 

 where it grows within reach of tide water, and is associated with 

 the equally local Cieuta Bolanderi, and flowers in July. 



Carduus occidentalis Nutt. Trans. Am. Phil. Soc. vii, 418. 



Very stout, 1 to 3 feet high ; the lanceolate pinnatifid leaves 

 densely white-tomentose beneath, only hoary-lanate or arachnoid 

 above ; heads 2 inches high, or larger, on long and stout peduncles ; 

 bracts of the involucre in very many series, all linear-subulate, ascend- 



