CXV111. GEXEKA OP PEEKS : 



Spore-cases few, loosely disposed, globose, furnished with a very 

 broad incomplete ring, of which from one-third to three-fourths 

 or more is wanting, (sometimes almost obsolete consisting only 

 of 3 4 strise). Indusium universal, formed of the membra - 

 naceous revolute margins of the narrow siliquiform segments. 

 Veins of the sterile fronds uniformly reticulated in oblique 

 oblong hexagonal areoles ; of the fertile few, longitudinal, dis- 

 tantly anastomosing. 



Fronds herbaceo-membranaceous, annual, proliferous, bi-tri- 

 quadri-pinnatifid, dimorphous ; segments of the fertile ones 

 linear, revolute, siliquiform. Rhizome short, erect. Aquatic 

 herbs. Parkeria differs only in the exaggerated reduction of 

 the strise of the ring. The reputed species appear to be doubt- 

 fully distinct. 



Ex. : C. thalictroides, Brongn. \ C. Parkeri, J. Sm. 

 C. Gaudichaudii, Brongn. \ C. Lockharti, Kze. 



Tribe OBMUNDISEJE. 

 (a) Fructifications paniculate. 

 166. OSMUNDA, Linnaeus, Gen. Plant. 778. 



pA, Cavanilles; STBUTHIOPTERIB, Eernhardi; PLENASIUJT, 

 Fred; OSMUNDASTBFM, Presl ; EIEDLEA, Mirbel, in part. 



Fructifications paniculate, terminal or lateral on contracted 

 rachiform portions of fronds, or occupying distinct contracted 

 fronds. Spore-cases crowded on the margins or over the surface 

 of the segments, obovate-globose, pedicellate or sessile, having 

 an incomplete or rudimentary gibbous ring, (represented by a 

 few parallel strise) near the apex, and bursting vertically in two 

 equal hemispherical valves. Veins forked, from a central costa ; 

 venules free. 



Fronds coriaceous or herbaceous, pinnate or bi-pinnate ; the 

 pinna; or segments often articulate ; fertile segments contracted, 

 usually rachiform, simple or compound, terminal medial or basal 

 on the fronds, or sometimes occupying distinct contracted fronds. 



