CETERACH OFFIC1NAKUM. 91 
/" CETERACH OFFICINA'RUM. 
THIS bears the various English names of Scaly Spleen- 
wort, Rough Spleenwort, Scale Fern, Scaly Hart's 
Tongue, and Miltwaste. 
The root is fibrous, black, tufted, and scaly at the 
crown, penetrating deeply into the old mortar of the 
walls, and into the clefts of the limestone rocks, on 
which it delights to grow. The fronds are evergreen, 
numerous, tufted, and spreading; varying in height 
from three to eight inches ; oblong, bluntish , deeply 
and bluntly indented at the edges, the indentations 
being alternate ; the margin of the leaf smooth. When 
growing in sheltered, shady situations, the indentations 
often are so deep as almost to render the fronds leafleted. 
Their upper surface is smooth ; in colour deep green, 
but slightly milky, or glaucous ; the upper surface of 
the mid-rib is scaly. The under side of the fronds is 
entirely covered thickly with pointed, saw-edged, brown 
scales, lapping over one another. Before the fronds are 
expanded these scales are white and silvery. The stalk 
of each frond is about one-fifth of its length, dark- 
coloured, and covered with pointed, brown scales. If 
the scales are removed from the under surface of the 
fronds, the fronds will be found to have alternate 
lateral veins uniting at their points near the edge of 
the frond. The seed, or sori, are in oblong narrow 
masses attached, except the lowest mass, to the upper 
side of the principal branches of the veins. The covers 
