CL. XXIV. J CRYPTOGAMIA FERNS. 389 



stalk scaly at the base. Fronds two feet high, erect, narrow below, 



yellowish-green, with longish stalks. Perennial: bears fruit in August : 

 grows on boggy heaths in England : rare. Eng. Bot. vol. xxx. pi. 2125. 

 Eng. Ft. vol. iv. p. 289. 1474. 



6. A.aculedtum. Common Prickly Shield-fern. Frond twice pinnate ; 

 leaflets egg-shaped, pointed, stalked, somewhat crescent-shaped, fringed 



with prickly serratures ; stalk and central ribs scaly. Fronds about 



two feet high, lance-shaped, dark-green. Perennial: bears fruit in July: 

 grows in woods and shadv places : common. Eng. Bot. vol. xxii. pi. 

 1562. Eng. Ft. vol. iv. p. 290. 1475. 



7. A. anguldre. Angular-leaved Shield-fern. Frond twice pinnate ; 

 leaflets egg-shaped, bluntish, stalked, fringed with bristly serratures, each 

 leaflet with a lateral lobe at the base, the lowermost elongated ; stalk and 



ribs scaly. Perennial : bears fruit in July : grows in woods and shady 



places. Eng. Fl. vol. iv. p. 291. 1476. 



8. A. labutum. Close-leaved Prickly Shield-fern. Frond twice pinnate ; 

 leaflets elliptical, pointed, decurrent, somewhat serrate; stalk and shaft 



scaly. Perennial : bears fruit in July : grows on shady hedge-banks: 



common. Eng. Bot. vol. xxii. pi. 1563. Eng. Fl. vol. iv. p. 291. 



9. A. spinuldsum. Pnckly-tonthed Shield-fern. Frond somewhat trian- 

 gular, smooth, twice pinnate ; leaflets decurrent, elliptical, deeply ser- 

 rate, with prickly teeth, their central rib undulated; stalk elongated, 



scaly at the base. Fronds about a foot high, smooth, light-green. 



Perennial : bears fruit in June and July : grows in marshy places : found 

 by Withering on Birmingham heath, and in Devonshire. Eng. Bot. 

 vol. xxi. pi. 1460. Eng.Fl. vol. iv. p. 292. A variety, with the lower 

 primary leaflets, twice pinnate, and not pinnate, is the A. dilatdtum, 

 Broad Sharp-toothed Shield-fern. Eng. Bot. vol. xxi. pi. 1461. Eng. Fl. 

 vol. iv. p. 293. 1478. 



10. A. Filix-f&'mina. Female Shield-fern. Frond twice pinnate ; 

 leaflets between oblong and linear, pinnatifid, serrate, pointless; stalk 



smooth ; sori oblong. Fronds about two feet high, lance-shaped, 



deep-green. Perennial : bears fruit in June and July : grows in moist 

 shady places : common. Eng. Bot. vol. xxi. pi. 1459. Eng. Ft. vol. iv. 

 p. 295. A small variety has been described as distinct, under the name 

 of A. irriguum, Brook Shield-fern. Eng. Bot. pi. 2199. Eng. Fl. vol. 

 iv. p. 296. 1479. 



5. CYSTE'A. BLADDER-FERN. 



Sori round, convex, variously scattered over the back of the 

 frond, between the central rib of each leaflet or lobe and the 

 margin. Cover white, round, concave, fixed by a narrow point 

 at the side of each sorus beneath. Capsules several, globular, on 

 short stalks, each one-celled, two-valved, bound by a jointed ring. 

 Seeds numerous^ roundish, very minute. Name from ciste, a 

 little box. 464. 



1. C. frdgilis. Brittle Bladder-fern. Frond between oblong and 

 lance-shaped, twice pinnate ; leaflets egg-shaped, pinnatifid, the lobes 



toothed or serrate ; partial stalks bordered ; sori crowded. Fronds 



from four to ten inches high, smooth, bright-green : stalk slender, dark and 



