About Myriopteris yavapensis (T.Reeves ex Windham) Grusz & Windham
Myriopteris yavapensis is a small fern that grows from a long creeping rhizome. The rhizome measures 1 to 3 mm in diameter and bears bicolored scales. Its leaves are scattered, reaching 7 to 35 cm in length and 2 to 6 cm in width, and grow from a dark brown petiole. The leaf blade ranges from oblong-lanceolate to nearly ovate in shape, and is up to 4-pinnate, or highly divided, at its base. The ultimate leaf segments are very small, round to oblong, and beadlike, with the largest segments typically measuring 1 to 2 mm in length. The lower abaxial side of the leaves is glabrous, or bears only a few small scales near the base. The upper adaxial side of the leaves appears sparsely pubescent, but is actually nearly glabrous; the few hairs present come from the rachis and costa, which also have abundant broader scales. The costae are green on their adaxial side for most of their length. They bear conspicuous overlapping abaxial scales that are up to 1 mm wide at their base, shaped lanceolate, truncate, to cordate, and usually covered in coarse cilia along their entire length. The edges of leaflets curl inward to form a false indusium that partially covers the sori. Myriopteris yavapensis is very morphologically similar to Myriopteris wootonii, and careful examination is required to correctly identify many specimens of this genus. Myriopteris yavapensis is native to mountain regions of Arizona, New Mexico, and Texas. It grows on rocky slopes and ledges, most often on igneous substrates, at elevations between 500 and 2400 meters.
