1917] Butters,— Studies in Ferns — Athyrium 193 
ATHYRIUM ANGUSTUM var. rubellum (Gilbert), new comb.' 
de filix-foemina rubellum Gilbert, List of N. A. Pterid. 35 
1901 
In the southern part of its range this variety appears to be merely 
the shade-form corresponding to the sun-forms discussed above, 
especially to the var. elatius, and its fronds are scarcely to be dis- 
tinguished from the sterile fronds of that variety. The variety 
rubellum, however, ranges much farther to the north and east than 
either forma typicum or var. elatius, which appear never to occur in 
regions of cool summers. 
The variety rubellum occurs throughout the range of the species, 
of which it appears to be the fundamental biological type, from which 
all the other varieties and forms have been derived. As here defined, 
it is not limited to forms with red stems, = hence . Al poor 
that we are obliged to adopt Gilbert’s nam 
authentic material of Gilbert’s variety, collected by Gilbert himself, 
Loewe his type locality, unquestionably belongs to the variety as here 
The following are the specimens of this variety in the Gray Her- 
barium 
NEWFOUNDLAND: barrens at the base of the serpentine tablelands, 
e Bay; August 27, 1910, Fernald and Wiegand no. 
‘ 908, Eames 
— Bay of Islands, August 9 ars 10, 1901, Howe and 
79; dry thicket, Bay St. George, August 5-7, ‘1901, aus aad bans 
989. 
Qvesec: low wet margin of Seal Cove River, Douglastown, Gaspé 
Co., August 22, 1904, Collins, Fernald and Pease; Bic, Rimouski Co., 
July 15, 1907, Fernald and Collins no. 817; Cap a PAigle, July 13, 
1905, John Macoun, herb. Geol. Surv. Canada no . 69251; Little 
Metis, August 21, 1906, James Fowler. 
Prince Epwarp Isanp: roadsides thickets and borders of dry 
woods, August 29, 1912, Fawald, cet aga St. John no 
New Brunswick: in partial shade along a fence, ‘Shediac Cape, 
August 2, 1914, F. T. Hubbard 
Nova Scotta: Baxter’s Harbor, July 10, 1900, F. G. Floyd no. 680; 
rich soil, edge of woods, Pictou, July 12-18, 1901, Howe and Lang no. 
547, dry woods, Pictou, July 12-18, 1901, Howe and Lang no. 546; 
rich moist bank, Yarmouth, June 22-29, 1901, Howe and Lang no. iii; 
Kentville, July 11, 1900, F. G. d no. 686. 
Marne: rich woods, Canton, August 1, 1908, J. C. Parlin 
i aoa woods, Randolph, July 7, 1894, E. F. Williams 
Alton} Bay, A. A. Eaton; low woods, Jaffrey, July 21, 1897, B. + 
1 See Plate 123, figure 13. 
