630 THE FEEN FAMILY. 



regious, and apparently in South America, but scarcely in North America. 

 One of the commonest of British Ferns. Fr. summer and autumn. The 

 barren fronds of young plants often resemble those of the broad. S., but the 

 fruiting ones are almost always very distinct. 



6. Crested Shieldfem. Aspidium cristatum, Sw. 



(Eng. Bot. t. 2125. Lastrea, Bab. Man.) 

 Resembles in some respects the male S., but the frond is less erect, the 

 pumas less regular, the segments broader, thinner, more wedge-shaped on 

 the lower side, nnich more toothed, and the lower ones sometimes almost 

 Ijiunatifid, the plant then forming some approach to the broad S., from 

 which it differs in the general shape of the frond much narrower, the seg- 

 ments much broader and much less divided. Sori large, with conspicuous 

 indusiums as in the male S. 



In moist or boggy places, in temperate Europe and western Asia, from 

 the Pyrenees and northern Italy to Scandinavia, and in North America, but 

 not generally common. In Britain, very local, but has been found in Nor- 

 folk and Suffolk, Nottinghamshire and Cheshu-e, in North Wales, and in 

 Ireland. Fr. summer and autumn. Some specimens appear almost to con- 

 nect it with the male S., whilst others are difficult to distinguish from the 

 broad S. 



7. Broad Shieldfem. Aspidium spinulosum, Sw. 



(Eng. Bot. t. 1460. A. dilatatum, t. 1461. Lastrea spinulosa, L. dilatata, 

 and L. Foenisecii, Bab. Man.) 

 The most variable of all our Shield/ems, aUied to the male S., but gene- 

 rally 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 di- 

 vided, either twice pinnate, with the segments of the pinaas oblong-lan- 

 ceolate and deeply toothed, or pinnatifid, or thrice pmnate : it then closely 

 resembles the ladi/ Spleenwort and the alpine Polypody, but may be 

 generally distinguished by the lower pinnas not decreasing so much in size, 

 and more accurately by the sori, which are cu-cular, with a kidney-shaped 

 indusium as in the male S., 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 tliree 

 at least have been considered as species, but have no tangible characters to 

 separate them. 



8. Rigid Shieldfem. Aspidium rig'idum, Sw. 



(Eng. Bot. Suppl. t. 2724. Lastrea, Bab. Man.) 

 Very near the broad S., 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 

 the male S. and the crested S. 



In rocky situations, especially in limestone districts, in temperate Europe, 

 from the Pyrenees to Norway, extending eastward into cetitral Asia, and in 

 North America. In Britain, cliiefly in the limestone districts of northern 



