144 Rhodora [AvcvsT 
and is called O. Montana, by Raf.”! In most such publications of 
Rafinesque's the names proposed are not associable with any state- 
ment of differential characters and the proposed names are therefore 
nomina nuda and not to be taken up. In the case of his Ozalis 
Acetosella, however, Pursh clearly stated important characters which 
differentiate our plant from the European, saying: “Flowers large, 
white, with red veins and yellow at the bottom; the petals are cuneate, 
emarginate, and narrower than the European species."? The char- 
acters of narrower, emarginate petals were the only points of differ- 
ence indicated by Bigelow who, like Rafinesque, may have taken 
his cue from Pursh; and it is clear that our plant should be called 
OXALIS MONTANA Raf. (1818) = O. americana Bigelow (1824). 
The form with purple petals should be called 
O. MONTANA Raf., forma rhodantha, n. comb. O. americana Bige- 
low, forma rhodantha Fernald, Ruopora, xx. 78 (1918). 
M. L. FEnNALD, Gray Herbarium. 
! Raf. Am. Mo. Mag. ii. 266 (1818). 
? Pursh, Fl. Am. Sept. i. 322 (1814). 
Vol. 22, no. 259, including pages 113 lo 128, was issued 3 August, 1920. 
