Asplenium ruta-muraria L. - Wall Rue
Family - Aspleniaceae
Stems - Short scaly rhizomes, dark brown. With fibrous, dark roots.
Leaves - To 10cm long, pinnately divided twice or three times, green, glabrous. Pinnae alternate, 1-3cm long. Pinnules spatulate, erose or just toothed at the apical margin.
Inflorescence - Sori one to many on the abaxial surface of the pinnae, linear. Indusium attached along one side of the sori.
Flowers - No flowers produced. Sporangia black, with 32 spores each.
Flowering - Spores produced May - September.
Habitat - Dolomite and limestone bluffs, in cracks and holes in the rock.
Origin - Native to U.S. and Europe.
Other info. - This neat little fern can be found in the southeastern Ozark region of Missouri. The plant is very easy to ID in the field as nothing else looks like it and it has a very limited habitat. The species is, however, rarely seen by casual observers as it grows along high bluffs and on rocky outcrops. This is a small plant which would look great in a shaded limestone rock garden.
Photographs taken near Jam Up Cave, Shannon County, MO., 6-22-03.