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ASPLENIUM Ruta-muraria*

White Maidcn-hair or Wall-rue.

CRYPTOGAMIA Filices.

Gen. Char. Fructifications in scattered lines. Invo-lucrum originating laterally from a vein, and burst-ing inwardly (that is towards the nerve). SmithMem. of the Fur in /lead. Vol. 3.

Spec. Char. Frond alternately twice compound;

leaflets wedge-shaped notched.

Syn. Asplenium Ruta-muraria, Linn. Sp. PI. 1541.

Iiudf. Fl. An. 453. With. Bot. Arr. V. 3. 53.

Relh. Cant. 389.

Ruta muraria. Raii Syn. 122.

Old walls and shady rocks produce this little fern not un-frequently, varying much in size according to the degree ofnourishment, or rather moisture, that it meets with. Thefructifications may be found early in summer in the best statefor examination, when the membrane which covers each lineis about to burst. The genera of ferns can only be determinedin that early state, as many whose involucra are widely differenthave the back of their fronds covered in an advanced state withone confused mass of capsules, and have hence been errone-ously referred to the genus of Acrostichum, as even the plantbefore us might be if only seen in such a state. This is not oneof the most easy to be determined in any state, but if care-fully examined it will be found that the membrane alwaysbursts towards an adjoining vein or nerve, and never towardsthe margin of the leaf without an intervening vein.

The root is perennial, of many dark thready fibres. Stalksupright. Fronds thick and rigid, a little inclined, of a darkglaucous green, smooth in every part. Involucrum notchedin the margin.