Astrolepis windhamii

Astrolepis windhamii D.M. Benham
(for Michael Windham, 1954–, cytogeneticist and pteridologist, formerly Utah Museum of Natural History, currently Curator of Vascular Plants, Duke Univ.)

Local names: Windham’s scaly cloak fern, Windham’s cloak fern

Leaves 10–50 cm long; longest pinnae 7–15 mm long, usually symmetrically shallowly lobed with 6–11 broadly rounded lobes, the lower surface concealed by scales, the upper surface with scales sparse, mostly persistent, elongate, stellate; n = 2n = 87 (Benham & Windham 1993). Rocky hillsides and cliffs on both limestone and igneous materials; Trans-Pecos (e.g., Brewster Co., Correll 13482, BRIT; El Paso Co., Correll 13832, BRIT; Val Verde Co., Correll & Correll 12903, TEX-LL [w of the Pecos River], annotated D.M. Benham) and extreme w Edwards Plateau (Uvalde Co., Correll & Correll 12876, TEX-LL; Val Verde Co., Z. Labus 37, TEX-LL, Seminole Canyon State Historical Park [e of the Pecos River], also Turner et al. 2003); AZ, NM, and TX; also n Mexico. Sporulating summer–fall. Mickel and Smith (2004) included A. windhamii within A. integerrima. However, we are following Benham (1992) and Benham and Windham (1993) in recognizing it as a distinct species. Based on isozyme studies (Benham 1989), they noted that it is an apogamous triploid containing three genomes (from A. sinuata, A. cochisensis, and an unnamed Mexican taxon related to A. crassifolia). In contrast, A. integerrima, while also an apogamous triploid, contains only two genomes (from A. cochisensis and the unnamed Mexican taxon). Because of their different origins, because they are reproductively distinct lineages, and because they are usually morphologically distinguishable (e.g., lobing of pinnae and scale characters) we believe recognition of A. windhamii at the species level is most appropriate. This species can usually be distinguished by its symmetrically shallowly lobed pinnae (vs. pinnae deeply lobed in A. sinuate and asymmetrically shallowly lobed or entire in A. cochisensis and A. integerrima). Benham and Windham (1993) noted that, “Although the features that separate these taxa are subtle, the pinna lobing and scale characteristics of A. windhamii … adequately distinguish them in most cases.”

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