northern spleenwort

Asplenium septentrionale is a small fern which grows in dense clusters superficially resembling tufts of grass. The long, dark stems support narrow, leathery leaf blades, which may appear slightly forked at the tip. The fronds are monomorphic, with no difference in shape or size between fertile and sterile fronds. The rhizome from which the many leaves of each plant spring is about 1 millimetre in diameter, and covered with scales. The scales are narrowly triangular, and range in color from black to a dark reddish brown. They are 2 to 4 millimetres (0.08 to 0.2 in) long, 0.3 to 0.6 millimetres wide, and entire (untoothed) at the edges. The stipes (the stalks of the leaf, below the blade) are reddish brown at the base, fading to green above. They range from 2 to 13 centimetres (0.8 to 5 in) in length, and are about 2 to 5 times the length of the leaf blade itself. The leaf blades are narrow, with parallel edges following the stem, ranging from 0.5 to 4 centimetres (0.2 to 2 in) in length and 0.1 to 0.4 centimetres (0.04 to 0.2 in) in width. They come to a point at both base and tip, and have a leathery texture. They are often divided into pinnae (leaflets) near the tip, usually two (but sometimes four). These pinnae are sharply angled towards the tip of the blade, giving it a forked appearance. They also come to a point at the tip, and have a few widely spaced, irregular teeth. …

Asplenium septentrionale subsp. septentrionale is found in Europe and Asia from the Macaronesian Islands east through Europe, western Asia, the former USSR, northern India, parts of western and central China (Xinjiang, Tibet, and Shaanxi), and Taiwan. It is also found in North America, principally in the Rocky Mountains of the western United States, but also in the Black Hills of South Dakota–Wyoming. It also occurs in the mountains of the Cascade Range and the Sierra Nevada, from Oregon south through California into Baja California. Populations occur to the eastward in western Texas and near the tip of the Oklahoma Panhandle, and two very disjunct stations have been located on shale in Monroe County and Hardy County, West Virginia. Asplenium septentrionale subsp. caucasicum has been reported from Georgia, Iran, Pakistan and Turkey. The type specimen of A. septentrionale subsp. rehmanii came from Pakistan, near the Lowari Pass. Asplenium septentrionale is epipetric and can be found in crevices of rocks, around boulders, and on cliffs. It can be found on a variety of substrates, including granitic rocks and limestone. The West Virginia stations are on shale. In the United States, it can be found growing at altitudes from 700 to 2,900 metres (2,300 to 9,500 ft).

Asplenium septentrionale is hardy to USDA Zone 4. It is best grown in partial sun or medium light in moist to dry potting mix. It requires good drainage and little watering. Sensitive to root disturbance, it is difficult to transplant and establish, and is rarely sold by nurseries.