442 Mutisieae 



1. C. Scolymus L. Stout and low, with very ample hoary- 

 tomentose bipinnatifid leaves ; involucral bracts ovate obtuse or 

 emarginate. 



An occasional escape from gardens. June-July. 



66. CENTAUBEA L. 



Annual or perennial herbs, with alternate entire den- 

 tate or pinnatifid leaves, and large or middle-sized heads 

 of variously colored flowers. Involucre ovoid or globose, 

 its bracts imbricated in many series, tipped with a stout 

 spine. Receptacle flat, bristly. Corolla-tube slender, 

 the limb 5-toothed or 5-cleft. Achenes oblong or 

 obovoid, compressed or somewhat 4-angled, obliquely or 

 laterally attached to the receptacle. Pappus of many 

 slender scabrous bristles or scales or rarely none. 



1. C. Melitensis L. (STAR-THISTLE.) Erect, branching, 5-8 

 dm. high, cinereous-pubescent or when young somewhat woolly ; 

 basal leaves lyrate-pinnatifid, those of the stem lanceolate, 

 mostly entire, narrowly decurrent; principal bracts with slender 

 spines of about their own length, spines pectinate-spinulose at 

 base, innermost with spinescent tips; flowers yellow; pappus of 

 very unequal rather rigid bristles or squamellate. 



A common weed in waysides and fields. July-November. Native of 

 southern Europe. 



Tribe 11. MUTISIEAE. PEREZIA TRIBE. 



Ours perennial herbs with subcoriaceous setulose- 

 ciliate alternate leaves. Involucral bracts imbricated. 

 Corollas 2-lipped, the outer lip 3-lobed, the inner 2-lobed. 

 Anthers caudate and with a long appendage at the apex. 



Represented with us by the single genus. 67. PEREZIA. 



67. PEREZIA Lag. 



Perennial herbs with mostly reticulated often setulose- 

 ciliate or spinulose leaves, and solitary cymose or panic- 

 ulate middle-sized discoid heads of rose-purple white 

 or blue flowers. Involucral bracts imbricated in few 



