CHARACTERS OF TRIBES AND GENERA. 569 
Sp. K. æsculifolia, Bl. (v v.) (K. Assamica, Griff., Hook., 
Journ. Bot., 2, t, 11, 12). 
Ozs.—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.—OPHIOGLOSSEA, R. Br. (Plate 29). 
Epigeous or epiphytal leafy plants, spores generated in + 
sudglobose, unilocular, coriaceous, homogenous, bivalved 
Sporangia, borne on special spikes or on panicles, 
Oss.—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 Ophioglossem is represented by the 
common Adder's-tongue Fern, O. vulgatum and Botrichum 
lunaria, which, with several congeners, have a wide 
E geographical range, being found in all countries between 
_ the limits of the south and north temperate zones. The E 
_ few epiphytal species are tropical or sub-tropical. : 
218.—Orn106L0ssuM, 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, ege Gi a 
special spike rising direct from the corm. ; 
Type. Ophioglossum vulgatum, Linn. 
| ‘Must. Hook. and Bauer Gen. Fil., t. 59 B. ; Moore id 
| e . Fil, p. 100 B.; J. Sm. Ferns, Brit. and For., fg. 155; d 
eme Syn. Fil, t. 9, fig. 73. ; 
