Rydberg : RocKV Mountain flora 429 



on Pachypodinin Nutt.* A generic diagnosis was given but no 

 species were cited. In Walpers' Repertorium (i : 172), the genus 

 was again taken up and the three species of Pacliypodiuni found 

 in Torrey and Gray's Flora, were taken up in the same order as 

 these. Hence TJicIypodiuni is a mere substitute for Pachypodinin, 

 which name had been used for another genus, and the type of the 

 latter genus is the type of the former. The three species oi PacJiy- 

 podiuui are the following, given in the order in which they appear : 

 P. laciniatiim, P. intcgrifolinin, P. sagittatuni. The last of the 

 three need not be considered, for in Torrey and Gray's Flora it is 

 regarded as doubtfully belonging to the same genus as the pre- 

 ceding and perhaps belonging to a section of Arabis. The type 

 o( Pachypodiinn Nutt., and hence of Thelypodhini Endl., must then 

 be either P. laciinatiiin or P. integrifoluim. There is nothing that 

 points directly to either of the two, but everything favors the for- 

 mer. It is not only the first species mentioned, but it is also the 

 only one previously known and figured. It was first described as 

 Macro podium laciniatnni. Hooker compared it with the original 

 M. nivale, gave figures for both and emphasized the differences 

 between the two, the oblong anthers and the long, slender pubes- 

 ent stipe of M. nivalc and the linear anthers and the short, stout 

 stipe of M. laciniatiun. Nuttall remarked " evidently not a Macro- 

 podiinn." It is evident that he selected the name Pachypodiui/i 

 from the short, stout stipe. 



If Macropodiitni laciinatiini Hook, is regarded as the type of 

 Thciypodii/m Endlicher, and the writer can not regard it otherwise, 

 the closest relatives of it we find in 7\ iitaJiciisc Rydb. and the 

 groups of Tliclypodia on which Dr. Greene based his genus Guil- 

 lenia. It is hard to see how Thclypodiiim lasiopliyllum Greene, 

 the type of the latter genus, can be generically distinct from T. 

 laciniaiiim (Hook.) Endl. Every character pointed out by Dr. 

 Greene for his Guillcuia agrees with the latter and is even found 

 in Hooker's description. It will be admitted that there are some 

 habitual differences, by which T. laciniatiim is isolated from Guil- 

 lcuia, but T. utahcnse, originally named T. laciniatiim, has the 

 habit of that genus, while the flower and fruit are essentially 

 those of T. lasiopliyllum. 



*T. & G. Fl. N. Am. i : 96. 1838. 



