334 



THE BOOK OF CHOICE FERNS 



H. Yalvatum — val-va'-tum (^valvate, having folding parts), Hooher and 

 GrevUle. 



This charming species, distinct in habit from all others, is a native of 

 Nicaragua, Guadelou23e, Martinique, and the Andes of Columbia and Peru, 

 where it grows on trunks of trees, sometimes entirely covering them. Its 

 broadly -triangular fronds, of an exceptionally dark green colour, 4in. to Gin. 

 long, and IJin. to 2 Jin. broad at the base, are produced from exceedingly 

 slender rhizomes (prostrate stems) of a wiry nature, lin. to 3in. long, slightly 

 winged above. They are tripinnatifid (three times divided nearly to the 

 midrib), with their rachis (stalk of the leafy portion) winged throughout and 

 their leaflets slightly hairy, the lower ones being triangular, with deeply-cleft 

 pinnules (leafits). The ultimate segments are conspicuously waved on each 

 side of the midrib. The sori (spore masses), twelve to twenty to a leaflet, 

 are terminal on the segments of the upper ones on both sides ; they are 

 provided with an egg-shaped involucre (covering) that is divided nearly to 

 the base, the valves being smooth or slightly ciliated.^ — Hooker and GreviUe, 

 Icones Filicum, t. 219. Lowe, New and Rare Ferns, Addenda, p. 182. 



The growth of this species is peculiar, as it takes place in autumn and 

 winter, when most other Ferns from the same habitats are comparatively 

 resting. Although not of a hirsute nature, it greatly dishkes water on its 

 delicate and exceedingly transparent fronds. 



H. Wilsoni — WiF-son-i (Wilson's). Synonymous with H. imilaterale. 



H. Zollingerianum — Zol-lin-ger-i-a'-num (Zollinger's), Kunze. 



A species of medium dimensions, native of Java, and in habit somewhat 

 resembling H. iwlyantlios, from which it diflers principally through the 

 apex of its flaccid fronds being elongated. — Hooher, Synojjsis Filicum, p. 62. 



