16 



and more divided leaves. These two are medium-sized thistles, 

 C. araneosus 5 to 7 dm. high, rather slender; C. laterifolius some-' 

 what larger. 



Where in an arrangement of the species of the genus do these 

 two, with a glutinous spot on the involucral bracts, belong? 

 They do not seem to belong with any of the species which have 

 been so characterized in the manuals; not, at least, with the 

 Undulati group, for the leaves are glabrate above. Possibly 

 they might be arranged with the Altissimi, but they lack the 

 general appearance of that group ; they have not the form of the 

 leaf or the shape of the head. They seem, rather, to belong to 

 the Carlinoides group, having a resemblance to C. Americanus . 

 If they are hybrids one of the parent forms would seem to be 

 C. Americanus, and the other some species with a glutinous spot 

 on the involucral bracts. In C. araneosus we would have to ac- 

 count for the arachnoid involucre, and in C. laterifolius foi the 

 broad leaf in the typical forms; in either case the parent form 

 does not seem to be available. Besides there seem to be hybrid 

 forms of C. Americanus and C. laterifolius, plants with broad 

 leaves, a glutinous spot on the involucral bracts, and fimbriate 

 bracts. Considering their general characteristics it would seem 

 that they belong with the Carlinoides group, near to C. Ameri- 

 canus. 



With the Carlinoides group also belong C. spathulatus Oster- 

 hout, and C. modestus Osterhout. ■ C. acicidatus Osterhout be- 

 longs with the Undulati, having a resemblance to the species of 

 that group. It has narrow involucral bracts, slender spreading 

 spines, and leaves tomentose on both sides. It is about as near 

 C. undulatus Nutt. as any of our Colorado species. 

 Windsor, Colorado 



SOME ABNORMAL POPLAR FLOWERS 



By George T. Hastings 



In April, 1916, a peculiar tree of the aspen— Fopul us grandi- 

 dentata — was found beside a new road on the talus slope of the 

 Palisades about opposite 220th Street, New York. The tree at 



