Aspidium. | ‘XOIV. FILICES. 561 
the Pyrenees and northern Italy to Scandinavia, and in North America, but 
not generally common. In Britain, very local, but has been found in 
Nottinghamshire, Yorkshire, Cheshire, and Renfrewshire in Scotland. 7. 
summer and autumn. Some specimens appear almost to connect it with A. 
Filix-mas, whilst others are difficult to distinguish from A. spinulosum. 
7, &. spinulosum, Sw. (fig. 1288). Broad Shieldfern.—The most 
variable of all our Aspidiums, allied to A. Filix-mas, but generally not so 
tall, of a paler green, and very much broader; the general outline nearly 
ovate, 1 to 2 feet long or rarely more, the lowest pair of pinnas not much 
shorter, or even longer than the others. ‘The frond is also more divided, 
either twice pinnate, with the segments of the pinnas oblong-lanceolate and 
deeply toothed, or pinnatifid, or thrice pinnate; it then closely resembles 
Asplenium Filix-foemina and Polypodium alpestre, but may be generally 
distinguished by the lower pinnas not decreasing so much in size, and 
more accurately by the sori, which are circular, with a kidney-shaped 
indusium as in A. Filix-mas, although much smaller, and when mature 
the indusium often disappears. | 
In sheltered, shady places, on moist banks, in open, moist woods, etc., 
common in Europe and Russian Asia, from northern Spain and Italy to 
the Arctic regions. Abundant in Britain. Fr. summer and autumn. 
More than twenty varieties of this species have received distinct names, and 
the following four have been considered as species, but have no tangible 
characters to separate them ; [they are,— 
a. A. spinulosum, Swartz. Frond oblong-lanceolate, glandular beneath, 
pale green. Lastrea spinulosa, Presl. 
b. A. dilatatum, Willd. Scales denser, narrower, with a dark-browncentre. 
Frond large, broader, dark green, glandular beneath. J. dilatata, Presl. 
c. A, remotum, Braun. Rachis of frond scaly. Frond glandular be- 
neath, oblong-lanceolate, pinules cut halfway down. Windermere only. 
Lastrea remota, Moore. 
d. A. emulum, Sw. Frond triangular, glandular beneath, concave and 
curved upwards, smelling of hay. Localin Britain. Nephrodium fenisecit, 
Lowe. 
8. A. rigidum, Sw. (fig. 1289). Rigid Shieldfern.—Very near A. 
spinulosum, of which it has the deeply toothed or pinnatifid, oblong- 
lanceolate segments, but the frond is stiffer and not so broad, and the sori 
are much larger, the two rows often occupying nearly the whole breadth 
of the segments, their indusiums conspicuous and persistent as in 4, 
Filia-mas and A. ecristatum. Lastrea rigida, Presl. Nephrodium rigidum, 
Desv. 
In rocky situations, especially in limestone districts, in temperate 
Europe, from the Pyrenees to Norway, extending eastward into central Asia, 
and in North America. In Britain, chiefly in the limestone districts of 
northern England. Fr. summer and autumn. Some botanists regard 
this and the two preceding species as varieties of 4. Filix-mas, into which 
they appear (when seen growing in profusion) to pass, through numerous 
intermediate forms. 
VIII. ASPLENIUM. SPLEENWORT. 
Fronds (in the British species) once, twice, or thrice pinnate or forked , 
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