Cheilanthes kaulfussii
Cheilanthes kaulfussii Kunze
(for G. Kaulfuss, 1786–1830, noted German fern botanist who in 1824 published Enumeratio Filicum)
Local names: Kaulfuss’ lip fern, glandular lip fern
Rhizomes short-creeping; leaves clustered, 8–35 cm long; petioles dark brown, flattened or slightly grooved distally on upper surface; leaf blades elongate- pentagonal (due to larger basal pinnae with enlarged proximal basiscopic pinnules), (3–)5–10 cm wide, 3-pinnate-pinnatifid to 4-pinnate at base, the pinnae not articulate, the ultimate segments not distinctly beadlike, glandular-pubescent on both lower and upper surfaces, resinous/oily due to exudate from the glandular hairs; costae without scales below. Rocky slopes and ledges, typically on igneous materials; Brewster (Chisos Mts.) (BRIT, TEX-LL) and Jeff Davis (TEX-LL) cos. in the Trans-Pecos and strikingly disjunct to Gillespie (O’Kennon 8379, BRIT), Llano (Correll & Correll 12766; Taylor & Taylor 13181, BRIT; D. Seigler et al. 2747, TEX-LL; Seigler 1977), Mason (C.M. Rowell et al. 2941, J.W. Stanford & T.J. Starbuck 476, BRIT), and Burnet (,i.J. M. Poole & W. A. Watson 1297, TEX-LL) cos. much further e; in the U.S. known only from TX; also Mexico, Central and n South America. Sporulating summer–fall. The disjunct occurrence in c TX of this species, which is usually found associated with igneous rocks, is a reflection of soil-related conditions of the Central Mineral Region, an island of igneous materials (Precambrian granites, gneisses, and schists) surrounded by escarpments of Paleozoic and Mesozoic limestone and sandstone (Walters & Wyatt 1982). For example, a Llano Co. collection (D. Seigler et al. DS-2747, TEX-LL) was made on Enchanted Rock. Populations in the U.S. appear to be polyploids (derived from diploid Mexican populations) that reproduce apogamously (Windham & Rabe 1993). Mickel and Smith (2004) noted that this is “one of the most widely distributed pteridophytes in Mexico.” This species “is covered with conspicuous glandular, stipitate hairs that exude a sticky light brown oil when fresh” (Yarborough & Powell 2002). It is similar to C. leucopoda in terms of leaf shape— elongate-pentagonal (= elongate 5-sided) which results from the basal or lowermost pinnae being largest. The basal pinnae have the pinnules closest to the rachis asymmetrically enlarged; the pinnules facing the base of the leaf (= basiscopic) are much larger. Cheilanthes kaulfussii can be distinguished from C. leucopoda both by its resinous/oily leaves, with short gland-tipped hairs, and by its dark petioles (versus leaves not resinous/oily with long non-glandular hairs and petioles straw-colored in C. leucopoda). Because of its rareness and limited distribution in the state, we consider this species to be of conservation concern in TX.