WESTERN SPECIES OF ARABIS. 69 



Some Western Species of Arabis. 



Every year of the last fifteen, by the arrival at my study 

 table of several specimens of Arabis from the farther West, I 

 have felt the desirability of a general summing up of the mem- 

 bership of this group of crucifers, in the form of a mono- 

 graph ; but the time for undertaking such a task still recedes. 

 Meanwhile a new invoice of these plants having lately come 

 in to me from northern California under promise on my part 

 that I would try to identify and report on them, I have been 

 impelled to make a renewed study of other material of this 

 kind lying in the National Herbarium hitherto unexamined. 



For my own convenience and that of others I shall first 

 present a short bibliography of my own contributions to the 

 knowledge of the genus made within the last ten or a dozen 

 years. 



A. rhodantha, Fendleri, Pitt, iii, 155. A. drepanoloba, 

 1. c. 306. A. Albertina, arida, campyloloba, connexa, consan- 

 guinea, duriuscula, eremophila, formosa, gracilenta, gra- 

 cilipes, maxima, oxylobula, oxyphylla, platyloba, recondita, 

 rectissima, tenuis, Pitt, iv. 189-198. 



A. Austinae, Covillei, epilobioides, inamoena, lycibergii, 

 Missouriensis, oligantha, peramoena, pratincola, trichopoda, 

 Feddes' Repertorium, v. 242-244. 



Out of a considerable number of new species here charac- 

 terized, only the first is at all closely akin to true Arabis, the 

 best representative of which in the farther West is A. Ble- 

 pharophylla of the coast of California. That and its allies are 

 marked by a truly green herbage which is of thin texture, with 

 no other than a sparse and bristly pubescence. The petals of 

 these, though purple in color, have a broad spreading limb, 

 and the pods are always straight and erect. 



Arabis aculeolata. More or less tufted montane peren- 

 nial, with subscapiform slender few-flowered stems 6 to 10 



L,KAFi,ETS, Vol. II, pp. 69-88. 11 May, 1910. 



