OF ARTS AND SCIENCES. 215 



is evidently a Crepis, of the Toungia section, although the scales of 

 the involucre become somewhat carinate, vv^ith a thickened midrib at 

 maturity. 



Crepis occidentalis Nutt. Nuttall could not have seen any well- 

 formed fruit of this when he characterized on it his genus PsilochcEiiia, 

 as having achenia " without any visible strite," and one of his own 

 sj)ecimens given to me by himself, and one of Wyeth's original collec- 

 tion given to Durand, are in flower only. At maturity they are in 

 fact strongly 10-striate-ribbed, fully as much so as in his own Crepis 

 {Leptotliecd) acuminata, with which the species is connected by such 

 gradations that it is very difficult to distinguish the two. TJie most 

 robust form of this variable G. occidentalis, which may be designated 

 as var. costata, has the thicker and almost columnar achenia costate by 

 10 very strong and salient ribs. Var. crinita is a remarkable form 

 from Oregon, with the involucre densely and the peduncles sparsely 

 beset with long and tortuous whitish bristles. 



Tkoximon Nutt. The union of Macrorhynchus Less, with Nuttall's 

 Troximon, now made by Bentham, appears to have been vmavoidable. 

 Troximon might, perhaps, have been restricted to one of the two origi- 

 nal species, T. cuspidatum, which has truly beakless columnar achenia, 

 with only a slight narrowing or indistinct neck under the summit. The 

 broad basilar areola is just that of Scorzonera, and the copious per- 

 sistent pappus is remarkably rigid, some of the longer bristles being 

 flattened and somewhat broadened downwards. This and the whole 

 aspect of the plant suggests a real transition in earlier times between 

 T. cuspidatum and the anomalous Microseris troximoides, described in 

 a preceding note. But T. glaucum, with an evident although short beak 

 to the mature achenium, and T. aurantiacum, with a more slender beak, 

 and both with persistent pappus of intermediate character, show such 

 a real gradation to Macrorhynclms as to render the reduction of Less- 

 ing's genus inevitable. These species, with T. parvijlorum {3Iacro- 



more persistent and naked." I cannot now verify this statement, which was 

 probably a mistal.en one. 



■i--i- FlavlflorEB, albo-lanatae, foliis ad basin caulis confertissimis, pedunculo 

 scapiformi 1-2-cephalo. Achenia ex Nutt. tenuiter 15-striata, coronula ob- 

 soleta. — Malacomeris Nutt. 



11. M. iNCANA Torr. & Gray, 1. c. Malacomeris incana Nutt. — San Diego, 

 on an island in the bay, Nuttall ; known only from his imperfect specimens. 



M. crepoides Gray, in Stevens, Exped. Pacif. R. R. Expl. is a Crepis: vide 

 supra. 



