276 CRYPTOGAMIA— FILICES. Aspidium. 



flavour of this root was detected by a good botanist, who had 

 taken it in Switzerland, in a quack medicine recommended for 

 worms in England, the cunning dealer in which would be glad 

 to bring it into general use as a purge. But there are many 

 drugs more safe, and better known in their operation. 

 This species was certainly never mistaken for A. cristatiim by the 

 writer of Engl. Bot. p. 1949 ; but Mr. Sowerby was deceived by 

 a wrong specimen, sent him from the Isle of Wight, which he 

 supposed, of course, to be correct, and from which he drew the 

 figure. The blunder was set right in v. 30. p. 2125 of the same 

 work. 



5. A. cristatum. Crested Shield-fern. 



Frond linear-oblong, almost doubly pinnate; leaflets de- 

 current, ovate, obtuse, crenate or pinnatifid, with little 

 sharp terminal teeth. Stalk scaly at the base. Masses 

 equidistant from the midrib and margin. Cover orbicular. 



A. cristatum. Sw. Syn. Fil. 52. Willd. Sp. PL v. 5. 252. Comp. 

 ed. 4. 173, Ejigl. Bot. v. 30. t. 2125. Hook. Scot. p. 2. 154. 

 Lond. t. 113, excellent. 



Polypodium cristatum. Linn. Sp. PI. 1551. Afzel. in Stockh. Trans, 

 for 1787. 256. t. 9. 



P. n. 848. Linn. Fl. Suec. ed. 1. 308 ; omitting the synonyms. 



P. Callipteris. Ehrh. Beitr. v. 3. 77. Crypt. 53. Uoffm. Germ. 

 V. 2. 6. 



Polystichum cristatum. Roth Germ. "v. 3. 84." 



On boggy heaths among coarse grass and other plants. Hooker. 

 Sent from the Lows on Holt heath, Norfolk, in 1805, by the 

 Pev. R. B. Francis. On bogs, amongst Alder bushes, at Wes- 

 tleton, Suffolk. Mr. Davy. 



Perennial. August. 



Root tufted. Fronds several, quite erect, readily distinguished 

 from the last, as Dr. Hooker observes, by their pale yellowish 

 green hue. But the present species is well characterized by 

 several other indisputable marks. Each/ro/J, at most two feet 

 high, is in its outline remarkably linear, not lanceolate ; nor is 

 it leafy throughout, but the stalk, beset towards the bottom with 

 large, rounded, brown, membranous scales, is destitute of leaves, 

 or wings, for about one-third of its height from the root. Leaves 

 tapering upwards from a broad base, quite smooth, truly pin- 

 nate, though their broad, ovate, blunt leojlets are decurrent, 

 and therefore somewhat confluent ; their margins are sharply 

 toothed, most copiously about the extremity, and the teeth end 

 in very short bristles. iUasses large, in simple rows, at an equal 

 distance between the midrib of each leaflet and its margin. 

 Cover tumid, white when fresh, permanent, soon becoming or- 



