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Height. From six inches to three feet. 
Colour. Light green. 
Habitats. Mountainous districts in Scotland. 
GROUP I; GENUS XI; SPECIES II. 
POLYPODIUM CALCAREUM. (Limestone Polypody.) 
Plate XV. 
Fronds. Triangular, bi-pinnate. Pinnae trianguar 
or lanceolate. The lowest pair, which are 
attached to the rachis by a bare stalk, so much 
larger than the rest as to give the frond a 
somewhat three-branched appearance. Pin¬ 
nules of the lowest pinnae pinnatifid ; those of 
the upper pinnae serrated. The under pinnules 
of the large pair of pinnae much larger than 
the upper ones. The surface of the frond 
covered with minute glands, imparting to it 
a characteristic mealy appearance. Stipes 
green, slightly scaly, and about as long as the 
rest of the frond. 
Growth. Fronds springing from a creeping, dark- 
coloured rhizoma ; rigid, but reflexed from the 
junction of the lowest pinnae with the rachis. 
Height. From six to nine inches. 
Colour. Dull green. 
