POLYPODY. 229 



somewhat crenulate at the margin, gradually decreasing in 

 size upwards, and are supported on a long, cylindrical , smooth 

 footstalk. The fructification consists of small yellowish brown 

 masses, called sori, arranged in a single series on each side 

 the midrib of the leaflets ; these groups are sometimes so nume- 

 rous as to be confluent. The sori are naked, i. e. not covered 

 by any tegument or involucre, and consist of numerous cap- 

 sules or conceptacles ; each of which is pedicellate, one-celled, 

 with an articulated ring, opening transversely with elasticity, and 

 ejecting the numerous minute sporules. Plate 38, fig. 1 (&) 

 mass of sori removed from the back of the leaf magnified; (c) 

 capsule magnified ; (c?) the same opening elastically and dis- 

 charging the sporules. 



Polypody is very common upon old walls, trunks and stumps 

 of trees, shady banks, &c. The fructification is in perfection 

 from June to November. 



The name Polypodium is derived from ttoXv, many, and 

 vovq, iroSoc, a foot, in allusion to the numerous roots, or to the 

 segments of the fronds. 



The leaves of this plant are sometimes burnt for the sake of its 

 ashes, which contain a large proportion of carbonate of potash. 



Qualities. — The rhizoma, (commonly called the root,) is 

 nearly inodorous; the taste is at first sweetish, becoming bitter, 

 nauseous, and slightly astringent. The aqueous infusion has 

 the flavour of the root, and is of a yellowish colour ; the ex- 

 tract is sweet, and scarcely bitter or astringent. The spirituous 

 infusion is much sweeter than the aqueous, but the extract is 

 somewhat acrid*. According to Bucholz, the rhizoma affords 

 saccharine matter, gum, resin, oil, and starch. 



Medicinal Properties and Uses. — The slight medicinal vir- 

 tues of Polypody have been quite obscured by the praises 

 lavished upon it by the ancients. Hippocrates, Theophrastus, 

 Dioscorides, Celsus, and Paulus Egineta attribute to it the 

 power of expelling bile and pituita ; consequently it was much 

 used in maniacal melancholic disorders, and in visceral obstruc- 

 tions -j\ Parkinson recommended it combined with Foxglove as 

 a remedy in Epilepsy (see Foxglove). The Polypodium quer- 



* Murray, App. Med. vol. v. p. 450. 



■f It is the " rheum purging Polypody " of Shakspeare. 



