General Notes. 187 



NOTE ON ARABIS PEDICELLATA A. NELSON.* 



My attention lias been called to this species again by coming across a 

 very close duplicate of the type in Mr. C. F. Baker's recently distributed 

 specimens from Nevada, No. 991. This on Dr. Greene's determination has 

 gone out as Parrya Mettziwii Greene. On looking up that species I find that 

 Arnb'is pedicdlata is quite specifically distinct from Parrya Menziesii, though 

 undoubtedly both should be referred to the same genus. My first thought 

 was that Arabis pedicellata would have to become Parrya pedicellata. Accord 

 ingly the distinction between the two genera came up for consideration. Be 

 tween Parrya proper and Arabis the distinctions may be fairly well drawn, 

 though they are no more pronounced than between the sections of Arcibisas 

 that genus is now constituted. On the other hand, the Phaenicaulis section of 

 Parrya and some of the species of A rabis are very closely related. The type 

 species, P. Menziesii, of this section has in turn been referred to a number of 

 different genera at different times, even by the same author. Nuttall inten 

 tionally and thoughtfully separated it from Parrya (T. & G. Fl. N. A. 1 : 89). 

 Dr. Greene coincides in this opinion (Bull. Torr. Bot. Club 13 : 143) at first, 

 but later remands it to Parrya (Fl. Fr. 253), while Dr. Watson refers it to 

 Cheiranthus. 



All these translocations seem to have had for their raison d'etre the re 

 puted peculiar habit and the broad straight flat ensiform pods. But in the 

 recent Nevadan specimens, cited above, these characteristics break down 

 (see description of A. pedicellata, 1. c. a description which seems 

 to need no change). The characters given below apply with equal 

 force to the PJiaenicaulis section of Parrya and to many typical species of 

 Arabis. 



Stems either erect or decumbent at base, from a woody caudex, leafy- 

 bracteate : leaves more or less clustered at base, entire: the cauline auri- 

 cled or sagittate at base : sepals erect, more or less gibbous at base : petals 

 clawed, with a patulous blade, exceeding the sepals: stamens 6, free and 

 unappendaged : pods linear or broader, nearly flat, more or less 1-nerved ; 

 replum not thickened ; stigma entire : seeds flattened, orbicular or elliptic, 

 winged or wingless ; the cotyledons accumbent. 



I am unable to find in literature or in the specimens at hand any 

 character to justify retaining Phaenicaulis either as a distinct genus or as a 

 section of Parrya. As suggested in Proc. Biol. Soc. Wash., 1. c., there are 

 some points in which a closer approach is made to Slrepianthus. 



Arabis Menziesii (Hook.) comb. nov. Hesperis Menziesii Hook. Fl. Bor. 

 Am. 1 : 60 ; Phaenicaulis ckeiranlkuides Nutt. in T. & G. Fl. N. A. 1 : 89. 



Aven Nelson. 



*Proc. Biol. Soc. Wash., 17 : 91. 



