122 OBSERVATION'S ON TOREIGN FERNS. 



countries by the tanners. The Ferns afford potash in considerable 

 quantity, and in my own neighbourhood, acres of the Pteris aqua- 

 Una (common brakes) are cut and burnt for ash balls, and their 

 efficacy is well known as an alkali, in softening the water for 

 washing. The beautiful AJiantum palatum is a considerable in- 

 gredient in the pleasant syrup of Capillaice : in the East Indies, 

 and other warm latitudes, where Ferns abound and luxuriate, the 

 roots of several, as Cyathea medullaris, Pteris esculenta, and Di- 

 plazium esculentum, are used for food. 



A frequent complaint against Ferns, by those who have not 

 studied them, is, their want of variety ; yet Sprengel in 1827 

 enumerated 1444 species, and many have since been added : but 

 the difficulty of recording their distinctive differences by descrip- 

 tion, without the aid of figures, and the scarcity and expense of 

 works on Ferns, with good plates, have deterred many from enga- 

 ging in the study of them, whose taste would otherwise have led 

 them to the pursuit. I hope that, before long, their proper and 

 more simple classification, with a clearer distinction of their gene- 

 ric distinctions, will be published by parties now engaged upon 

 such a work, and at a price not incompatible with the increasing 

 taste for this study. In the meantime, I recommend drying and 

 pressing the fronds for examination as the best means of having 

 their species ascertained ; and as they are easily done, and retain 

 their form and beauty better than the flowering plants, they are 

 ornamental as well as instructive. If this were generally done, I 

 feel persuaded that many local varieties of the British Ferns would 

 be found, and interchanges made with mutual advantage. 



The greater proportion of Ferns multiply by radical onsets, and 

 the tubers of some are produced not only under, but above the soil ; 

 as especially seen in Davallia Canariensis (Haresfoot Fern), Po- 

 typodium Cagopodioides, Aspidium tuberosum, &c. In the Aspi- 

 dium bulbi/crum, small pseudo-bulbs are produced attached to the 

 mid-rib, and these falling to the ground when ripe, reproduce the 

 species. In the Pteris arguta, I have found small bulbs at the 

 roots, from which I have occasionally raised young plants. That 

 beautiful little Fern, the Aspic nium JlabeUifolium, takes root from 

 the point of its long pendulous frond, and will even, without the 

 point touching the soil, strike out a root and fresh plant; but 

 which, oi" course, will soon perish, having nothing to grow in. 



