Stems compact to short-creeping; stem scales uniformly tan or somewhat darker near base, to 15 mm, margins ciliate-dentate to entire. Leaves 10--50 cm. Blade pinnate-pinnatifid, pinna pairs 20--45. Pinnae ovate to deltate, largest 7--15 mm, usually symmetrically lobed, lobes 6--11, broadly rounded, separated by shallow sinuses; abaxial scales concealing surface, lanceolate, usually 1--1.5 mm, ciliate with coarse marginal projections; adaxial scales sparse, mostly persistent, elongate, usually stellate, attached at base, body 2--4 cells wide. Sporangia containing 32 spores. n = 2 n = 87, apogamous.
Sporulating summer--fall. Rocky hillsides and cliffs; occurring on calcareous and noncalcareous substrates; 1200--2100 m; Ariz., N.Mex., Tex.; n Mexico.
Recent isozyme analyses (D. M. Benham 1989) indicate that Astrolepis windhamii is an apogamous allotriploid that contains three different genomes, one each from A . sinuata , A . cochisensis , and an unnamed Mexican taxon related to A . crassifolia . Because of this genomic constitution, Astrolepis windhamii tends to bridge the morphologic gap between A . sinuata and A . integerrima , which is itself a hybrid between A . cochisensis and the unnamed Mexican species. Although the features that separate these taxa are subtle, the pinna lobing and scale characteristics of A . windhamii mentioned in the key adequately distinguish them in most cases.
Common Name: Windham's scaly cloakfern
General: Stems compact to short-creeping; stem scales uniformly tan or somewhat darker near base, to 15 mm, margins ciliate-dentate to entire.
Leaves: Leaves 10--50 cm. Blade pinnate-pinnatifid, pinna pairs 20--45. Pinnae ovate to deltate, largest 7--15 mm, usually symmetrically lobed, lobes 6--11, broadly rounded, separated by shallow sinuses; abaxial scales concealing surface, lanceolate, usually 1--1.5 mm, ciliate with coarse marginal projections; adaxial scales sparse, mostly persistent, elongate, usually stellate, attached at base, body 2--4 cells wide.
Sporangia: Scattered along and not concealed by the plane, un-recurved pinna margins.
Ecology: Rocky hillsides and cliffs on calcareous and noncalcareous substrates; 1200--2100 m (3937-6890 ft).
Notes: Distinguishing characters for the genus are once-pinnate leaves with lobed pinnae, dense scales covering pinnae under-surfaces and dense to sparse stellate scales on the upper surfaces. This species is one of the two larger, more robust Astrolepis species (the other is A. sinuata) and is distinguished by the larger, symmetrically-lobed pinnae (7-35 mm) with more rounded lobes than sinuata; and the sparse scales on upper-surfaces, the scales 2-4 cells wide and appearing more round and thick than the similar sinuata. These species can be cryptic and it-s best to compare samples before being able to ID independently in the field. This is an apogamous (reproduce with no fertilization) allotriploid with genomes from A. integerrima, A. cochinensis and a third, unamed taxon and contains characters of the other species, all indicating a complex hybrid origin.
Ethnobotany: unknown
Etymology: Astrolepis is from the Greek astron, a star, and lepis, scale, which refers to the scales on the blade surface,
Synonyms: None
Editor: FSCoburn 2015
