CHAPTER III, 



O N C L E A , Mettenius. 

 (On-oc'-le-a.) 



Sensitive and Ostrich- feather Ferns. 



HIS genus, which comprises only three species of Ferns 

 inhabiting cold and temperate regions, derives its name from 

 orios, a vessel, and kleio, to close, in allusion to the singularly 

 rolled-up character of the fructification. It is a small sub- 

 division of the tribe Dicksoniece, and forms, in Hooker and 

 Baker's " Synopsis Filicum," Genus 9. The distinctive characters of Onoclea 

 are so striking that the plants cannot possibly be mistaken. The principal of 

 these characters is the disposition of the sori (spore masses), which form 

 a fertile frond entirely differing from the barren ones in texture as well as in 

 general appearance. They are globose, situated on the veins of the changed 

 or contracted leaflets, with the revolute (turned-back) margin of which they 

 are quite concealed. Sometimes the sori are covered with a very thin, delicate, 

 half- cup -shaped involucre, originating from the under -side of the sorus ; in 

 many instances, however, this covering is wanting. In one of the three 

 species, 0. sensibilis, the stems are of an underground -creeping nature ; whereas 

 in the others the stem, or caudex, occupies an uj>right position. In all cases 

 the fronds are stipitate (borne on stipes or stalks), pinnate (once divided to 

 the midrib) or pinnatifid (divided half-way to the midrib), and their veins are 

 either free or intercross one another. 



Onoclea and Struthio])teris have been united by Mettenius, the plants, 

 of a hardy nature, being natives of North America, Sikkim, Japan, and 



