Cheilanthes lindheimeri
Cheilanthes lindheimeri Hook.
(for F.J. Lindheimer, 1801–1879, German-born TX collector)
Local names: Lindheimer’s lip fern, fairy-swords
Rhizomes long-creeping, the scales uniformly brown; leaves closely scattered, 7–30 cm long; petioles usually dark brown, rounded on upper surface; leaf blades oblong-lanceolate to ovate-deltate, 2–5 cm wide, 4-pinnate at base, the pinnae not articulate (= dark color of stalk stopping at base of pinna), the ultimate segments rounded, bead-like, tiny, the largest 0.7–1 mm long, nearly glabrous on upper and lower surfaces (but appearing densely tomentose on upper due to the scales of costae having curly, tangled marginal cilia); scales on underside of costae conspicuous, often concealing ultimate segments, long-ciliate with the curly cilia forming an entangled mass; n = 2n = 90 (Windham & Rabe 1993). Rocky slopes and ledges; mainly Edwards Plateau and Trans-Pecos but scattered n to Palo Pinto (G.M. Soxman 114, TEX-LL) and Parker (W.R. Carr 10495, TEX-LL) cos., e to Burnet Co. (Whitehouse 18437, BRIT), and s to McMullen Co. (Turner et al. 2003); AZ, NM, OK (Comanche Co.—OK Native Plant Database 2009), and TX; also Mexico. Sporulating Mar–Nov. [Myriopteris lindheimeri (Hook.) J. Smith] Jack Stanford (pers. comm.) noted that this species is found on both granite and limestone. Jim Blassingame (pers. comm.) commented that this species spreads prolifically by rhizomes. It is primarily an apogamous triploid of autopolyploid origin, though 3 diploid populations have been discovered (Schuettpelz et al. 2008). Lindheimer’s lip fern is similar to C. wootonii and C. yavapensis, but the broad, uniformly colored rhizome scales, the very small ultimate leaf segments (1 mm or less wide), and the upper leaf surfaces appearing to be densely hairy (actually due to curly, tangled, marginal cilia on the costal scales) are helpful in identification. Although a number of TX Cheilanthes species have long-creeping rhizomes with the leaves closely scattered along the rhizomes, this is the only such species that occurs e of the Trans-Pecos (with the exception of the extremely rare C. lanosa which can sometimes have the rhizomes long-creeping). These long-creeping rhizomes distinguish C. lindheimeri from the somewhat similar C. eatonii and C. tomentosa. Lindheimer’s lip fern is sometimes called fairy-swords because of the upright position of the elongate leaves and their pale appearance due to cilia on the costal scales.