COM POSIT j:. 475 



firmer, appressed, not cleft, but with a dilated and spinescent tip. Re- 

 ceptacle densely setose-paleaceous. Flowers yellow. Achenes obpyra- 

 midal; those of the marginal row more plump, somewhat convex and 

 gibbous on one side, more angular on the other; those of the disk more 

 regularly and sharply rhombic-tetragonal; all truncate at the broad 

 summit and surrounded by a crenulate margin. Pappus of the outer 

 row of achenes reduced or wanting; of the others double, namely with 

 an outer set of elongated but unequal ciliate palese in several series, 

 and an uniserial and much shorter inner set. 



1. C. LANATUM, DC. in Duby, Bot. Gall. 2 ed. 293 (1828); Linn. Sp. PI. 

 830 (1753), under Cartharnus. A very rigid thistle-like yellow-flowered 

 annual, naturalized about South San Francisco, Bioletti. 



110. SILYBUM, Vaillant. Coarse and stout annual, with very large 

 sinuate-piunatifid prickly leaves veined and blotched with white. Heads 

 large, at the ends of long pedunculiform branches. Involucre broadly 

 ovoid; bracts foliaceous, spinose along the margins, tapering into a rigid 

 prickle. Receptacle densely soft-bristly. Corollas all alike, red-purple. 

 Stamens monadelphous below. Achenes compressed and smooth. 

 Pappus multiserial, of narrow almost setiform barbellate palese which 

 are united slightly at base, and deciduous in a ring. 



1. S. Marianum, Ga^rtn. Fruct ii. 378 (1802); Linn. Sp. PL ii. 823 

 (1753), under Carduua. — One of the most common and troublesome of 

 rank thistles, in all waste lands in California. 



111. CYNARA, Vaillant. Very stout perennials, with pinnatifid or 

 bipinnatifid sessile though not decurrent leaves; the lobes spinescent- 

 tipped. Heads very large; involucral bracts coriaceous. Receptacle 

 fleshy , timbrillate. Achenes obovate, compressed and somewhat ^-angled. 

 Pappus of many series of plumose bristles. 



1. C. ScoLYMUs, Linn. Sp. PI. ii. 827 (1753). (Artichoke.) Stout 

 and low, with very ample hoary-tomentnlose bipinnatifid leaves, the 

 segments spine- tipped: involucral bracts ovate, obtuse or emarginate.— 

 Escaped from gardens near Benicia, West Berkeley, Alameda, etc. 



112. SCOLYKVS, Toil rnefort. Rigid erect herbs, with coarse decur- 

 rent pinuately lobed and spinescent leaves, and rather large heads 

 solitary or glomerate at the ends of the branches. Involucre ovate, 

 leafy-bracted at base, the proper bracts scarious-margined and spiuescent- 

 tipped. Receptacle paleaceous, the paleae more or less embracing the 

 achenes. Pappus a crown of scarious palese. 



