THE PERM ALLIES 



29 



or short stalked, in the various species. In Ophioglossum 

 the sterile portion is simple, and 

 in all our species except the anoma- 

 lous O. palmatiim appears like a sin- 

 gle leaf borne on the common stalk. 

 In Botrychhim (Fig. 19) the sterile 

 segment (except in some forms of 

 B. simplex) is somewhat pinnately or 

 ternately divided, and in the larger 

 forms of B. Virgintanwn is broad- 

 ly ternate, with the divisions even 

 tri — quadripinnatifid. The veins are 

 free in the latter genus, but anas- 

 tomose in the former. This charac- 

 ter, however, is frequently obscured 

 by the fleshy texture of the plant. 



83. Vernation. — As has been 

 before stated, ferns are rolled in the 

 bud from the apex downward {cir- 

 cinate), distinguishing them from 

 the higher forms of vegetation. 

 Among the Ophioglossace^, how- 

 ever, the vernation is either straight, 

 inclined at the apex of one or both 

 segments, or else the fertile seg- 

 ments are folded on the main stalk, 

 making the vernation wholly in- 

 clined. Until recently there has been 

 much difficulty in distinguishing the 

 smaller species of Botrychiuin, and 

 some forms seem to connect the 

 smaller ones with the reduced forms 

 of B. tertiatum and B. Virgini- 

 anuin. 



Mr. Davenport has investigated the bud characters of these 

 intimately related species, and has made their identification a 

 matter of comparatively easy investigation. The buds may be 

 found enclosed in the base of the common stalk (except in /?. 

 Virginianum, where they are placed in an upright cavity at one 



Fig. 19. — Plant of Botrychium 

 lunaria, natural size. 



