Polypodium Calcareum, J . E. Smith. 
Gymnocaepium Robeetianum, Newman. 
RIGID THREE-BRANCHED POLYPODY. 
Root—F ibrous and black; rhizome black and creeping, 
from which the fronds spring at intervals. 
Frond— Subternate, rhomboid-triangular (the base, or 
outline below the broadest diameter, being in the majority 
of Matlock specimens, a little longer than the sides; one 
measuring 22 inches, is at the base of the frond 11J inches 
wide, while the sides are only 9J inches deep), three- 
branched: basal branches, lower half pinnate, upper half 
pinnatiiid; the upper branch pinnate, apices acute. 
Stipes —About two-thirds the length of the frond, much 
firmer and stronger than in P. Dryopteris, sparingly 
covered with scales. 
PiNX.E—Triangular-lanceolate, pinnatifid, the lower pinnae 
and pinnules being longer than the upper. 
Pinnules — Oblong, obtuse, somewhat serrated. 
Venation— Mid vein sinous, lateral veins simple and 
branched. 
Fructification — Circular clusters of capsules, marginal 
when in perfection. 
Habitat —Rocky places, in limestone districts, upon deep 
loose stones: thrives in sunshine. Locally abundant about 
Matlock, Buxton, Miller’s Dale, &c. 
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