Rydberg : Rocky Mountain flora -V>7 



green and glabrate on the upper side" against "Leaves permanently 



tomentose on both sides." The glabrate character is cornet 

 as far as C. filipendulus in concerned and was the reason why 

 Dr. Gray associated it with C. altissimus; but it is not true of 

 C. Flodmanii, for in that species the tomentum is as permanent 

 as in C. undid a tits and C. ochrocentrus and far more so than in 

 C. megacephalus. In the key C. filipendulus is characterized, 

 but the description is of C. Flodmanii under a wrong name. Dr. 

 Gray included C. Flodmanii in his Cnicus undnlatus canescens 



Professor Nelson has admitted a variety Carduus undnlatus 

 canescens (Nutt.) Porter. Evidently this was unknown to him 

 for he simply copies Gray's characterization of Cnicus undnlatus 

 canescens. Some years ago, while visiting the Gray herbarium, 

 I was curious to see what Gray meant by this variety. I found 

 that it contained a mixture of Carduus Flodmanii, C. oblauceolatus, 

 another related species of Arizona, and Cirsium brevifolius Nutt. 

 The last is a yellow- flowered species related to Carduus Nelsonii 

 and C. plattensis, and antedates both. Of these C. Flodmanii 

 agrees best with the description of Cirsium canescens Nutt., and it 

 might be that species. I have seen, however, a specimen of another 

 species with strong erect involucral spines, which bore the name 

 Cirsium canescens in Nuttall's own handwriting. Whether that 

 specimen was the type or not I do not know, but I have adopted 

 the name Carduus canescens for that species. Pammel in his 

 treatise on the Iowa thistles adopted the name Cnicus canescens 

 for Carduus Flodmanii. If Nelson had followed him, I would not 

 have made any criticism, as there is some doubt as to which the 

 name canescens belongs to, C. Flodmanii or the species for which 

 I have adopted it. 



Professor Nelson has also omitted all the Utah species described 

 by Marcus E. Jones, although most of them belong to the range 

 of the New Manual. 



Centaurea and Arctium 



Neither of these two genera are included in the New Manual, 

 although C. Cyanus has been collected at several places in Mon- 

 tana, C. solstitialis L. at Salt Lake City, Utah, and A. minus 

 Schk. in Colorado. 



New York Botanical Garden. 



