THE BRITISH FERNS. 
Genus XVIII: BOTRYCHIUM, Swartz. 
Gen. Cuar.—Fructifications paniculate, formed of numerous 
secund spikelets, on a distinct branch of the frond. Spore-cases 
erect, biserial, sessile, globose, fleshy-coriaceous, ringless, bursting 
equally in two equal hemispherical valves. Veins flabellate-dicho- 
tomous, or dichotomo-furcate from a central costa ; venules free. 
Fronds herbaceous or sub-carnose, the sterile and fertile branches 
distinct, the branches pinnatifid pinnate or ternately decompound. 
Caudex cormiform, short, erect, fleshy. 
The genus Botrychium, belongs to the Ophioglossaceœ, a distinct 
group of Ferns from any we have been considering, distinguished 
primarily by having the spore-cases altogether ringless, and by hav- 
ing the fronds straight in vernation, that is to say, folded flat in the 
embryo state, and not curled in a circinate manner, as is almost 
universal in the family of Ferns. 
Of this group we have two British genera, Botrychium and Ophio- 
glossum, the native species of which are readily distinguishable from 
each other by their external features. Both genera have two- 
branched fronds, one branch forming, as it were, the leaf, and the 
other the inflorescence-like fructification ; but they differ obviously 
in this, that Botrychium has its branches again branched, while the 
branches in Ophioglossum are simple or undivided. 
Mr. Newman has very well described in the following passage," 
the mode in which these interesting plants are developed :— 
“The roots and eaudex of Botrychium differ essentially from those 
of true Ferns. The roots are stout, succulent, and brittle. The 
caudex is about the same size as the roots, perhaps rather stouter ; 
it descends perpendicularly, and the roots issue from it at right angles. 
Before the plant has felt the influence of spring, the frond exists in 
* Newman, History of British Ferns, 3 ed. 315. 

