THE COMMON MOONWORT. 325 
Caudex or Corm-tike Crown forming a small scarcely thickened 
wiry-rooted descending axis (rhizome, Presi), terminated by a bud or 
growing point, enclosed by brown membranaceous sheaths. Roots 
stoutish, fleshy, brittle, branched and elongated, spreading irregularly 
from about the crown; and branching in a somewhat whorled 
manner from the perpendicular axis beneath the crown; some of 
the stouter of these roots probably organise new crowns, as in the 
case of Ophioglossum. When at rest, the plant consists of this 
crown or bud or growing point, seated among the wiry roots, 
enclosing the incipient or rudimentary fronds, and encased by mem- 
branaceous sheaths. 
Vernation plicate or folded straight, the fertile branch clasped by 
the sterile one. à 
Stipes erect, smooth, cylindrical, hollow, succulent, having about 
four vascular bundles embedded in its tissue, its base surrounded by 
long brown sheaths, which are doubtless the persistent bases of 
former fronds, usually about half the height of the entire frond, 
dividing at top into two branches, of which one is leafy, the other 
fertile. 
Fronds from two to eight or ten inches high, including the stipites, 
firm, stout, fleshy. Sterile branch smooth, dark green, pinnate, 
with four to six or seven pairs of pinne, which are flabellate or 
lunate, the margins nearly entire, oï somewhat crenate. Fertile 
branch pinnate or bipinnate; the narrow rachiform spikelets 
(whether answering to pinne or pinnules) fleshy, flattened, and 
bearing on the inner face or that towards the sterile branch a double 
row of erect spore-cases, so that these spikelets are secund, and they 
are moreover more or less incurved, or suberect. Sometimes more 
than one fertile branch is produced, and occasionally spore-cases are 
developed on the edges or surface of the barren pinnæ. 
Venation of the barren pinne flabellate-furcate, i. e. the vein 
enters at the base, and becomes forked over and over again until 
the whole space is traversed by the contiguous slightly radiating 
veins and venules, which do not extend quite to the margin. 
Fructification occupying the flattened rachiform divisions of the 
separate fertile branch of the frond. Spore-cases sessile, standing 
erect, i.e. at a right angle to the plane of the segments, in two 

