CHARACTERS OF TRIBES AND GENERA. 367 



Sp. K. aesculifolia, Bl. (v v.) (K. Assamica, Griff., Hook., 

 Journ. Sot., 2, t. 11, 12). 



OBS. The under side of the frond of this Fern is 

 peculiar in being covered with stomata-like pores. 



Evolution of the fronds straight. 

 Tribe 29. OPHIOGLOSSE^], R. Sr. (Plate 29). 



Epigeous or epiphytal leafy plants, spores generated in 

 sudglobose, unilocular, coriaceous, homogenous, bivalved 

 sporangia, borne on special spikes or on panicles. 



OBS. This tribe is distinguished by the vernation of the 

 fronds being straight, not spirally coiled, as in what is 

 generally called true Ferns ; it consists of about twenty 

 species, comprehended under the three following genera. 



In this country Ophioglossece is represented by the 

 common Adder's- tongue Fern, 0. vulgatum and Botrichum 

 lunaria, which, with several congeners, have a wide 

 geographical range, being found in all countries between 

 the limits of the south and north temperate zones. The 

 few epiphytal species are tropical or sub-tropical. 



218. OPHIOGLOSSUM, Linn. (1737). 



Fronds ovate elliptical, lanceolate, entire or long and 

 linear, dichotomously forked or palmate. Veins reticulated. 

 Sporangia connate, in two rows, forming a distichous, 

 spike, produced from the disk of the frond, rarely a 

 special spike rising direct from the corm. 

 Type. Ophioglossum vulgatwn, Linn. 

 Illust. Hook, and Bauer Gen. Fil., t. 59 B. ; Moore Ind. 

 Fil., p. 100 B. ; J. Sm. Ferns, Brit, and For., fig. 155 ; 

 Hook. Syn. Fil., t. 9, fig. 73. 



