CHAPTER V, 



CERATOPTERIS, Brongniart. 

 (Cer-at-op'-ter-is.) 



Floating Stag's-Horn Fern. 



Y some authors this very anomalous genus is regarded as 

 a distinct sub-order, and by others it is placed in Polypodiece. 

 It derives its name from keras^ a horn, and 'pteris.^ a Fern, 

 on account of the singular appearance of the fructification, and 

 forms Genus 32 in Hooker and Baker's " Synopsis Filicum." 

 Ceratopteris is composed of a solitary very curious and handsome, stove 

 species, C. thalictroides, of annual growth. The sori (spore masses), which 

 are produced in abundance, are placed on two or three veins running down 

 the frond longitudinally, and are nearly parallel with both the edge and the 

 midrib ; they are covered by an involucre formed of the reflexed margin of 

 the frond, turned back in such a way that the two sides meet against the 

 midrib. The capsules, which are stalkless and nearly spherical, are scattered 

 on the receptacles and provided with a ring, which is sometimes entire, 

 incomplete, or even obsolete. 



Culture. 



Eaton, in his excellent work on North American Ferns, says (p. 256) : 

 C. thalictroides "is an annual, growing from the spore, forming its pro- 

 thallus with the antheridia and archegonia producing its embryo, and 

 growing first into a plantlet with minute, obovate fronds, and soon into 

 a mature plant, buoyed up by the spongy leaf- stalks of its fronds, and later 

 on sending up into the air fully -developed sterile and fertile fronds, and at 

 last dying and contributing its proportion of decaying vegetable matter to its 

 native lagoons." In a cultivated state the spores must be preserved ; they 



