Note: Collection 2902, pro parte. Sherff cited K sheet only, and added "pro parte" after collector number but did not explain why; in his monograph (1935: 97), however, he cited several other sheets of this collection under D. laxa var. laxa (F [2], G, GH, LE, NY, P [2]), excluding them from his new variety. Heller (1897:918) mentions that the "broad and narrow leaved forms being found side by side." Sherff was obviously segregating material of the two forms, naming the broad leaved one as D. laxa var. obovata. Sherff did not cite a date in the original publication, but cited 2 November in his monograph.

Note: Collection 2902, pro parte. Sherff cited K sheet only, and added "pro parte" after collector number but did not explain why; in his monograph (1935: 97), however, he cited several other sheets of this collection under D. laxa var. laxa (F [2], G, GH, LE, NY, P [2]), excluding them from his new variety. Heller (1897:918) mentions that the "broad and narrow leaved forms being found side by side." Sherff was obviously segregating material of the two forms, naming the broad leaved one as D. laxa var. obovata. Sherff did not cite a date in the original publication, but cited 2 November in his monograph.

*Verification: Wagner, W.L. & R.K. Shannon. 1999. Brittonia 51:422-438.