Stem scales concolored, margins black, undifferentiated, thick, ciliate. Leaves 8--35 cm. Petiole black, much shorter than blade, rounded adaxially, covered with ciliate and stellate scales. Blade lanceolate, usually 2-pinnate, 3--6 times longer than wide, abaxially with whitish or yellowish farina completely concealed by overlapping ciliate and deeply dissected stellate scales, adaxially with scattered stellate scales; basal pinnae equal to or slightly smaller than adjacent pair, ± equilateral, proximal basiscopic pinnules not greatly enlarged. Ultimate segments sessile to subsessile, narrowly adnate to costae; segment margins slightly recurved, rarely concealing sporangia. Sporangia containing 32 spores. n = 2 n = 90, apogamous.
Sporulating summer--fall. Rocky slopes and cliffs, apparently confined to limestone; 300--1900 m; Ariz., Tex.; Mexico.
Although Notholaena aschenborniana is often described as nonfarinose, the abaxial glandular farina characteristic of all species of Notholaena as defined here is present beneath the dense covering of scales. All individuals examined chromosomally by M. D. Windham (unpublished data) were apogamous triploids that apparently arose through autopolyploidy. Further investigation is necessary to determine whether or not 64-spored, diploid populations of N . aschenborniana are still extant.
Common Name: scaled cloak fern
General: Stem scales concolored, margins black, undifferentiated, thick, ciliate.
Leaves: 8--35 cm long; petioles black, much shorter than blade, rounded adaxially, covered with ciliate and stellate scales; blade lanceolate, usually 2-pinnate, 3--6 times longer than wide, abaxially with whitish or yellowish farina completely concealed by overlapping ciliate and deeply dissected stellate scales, adaxially with scattered stellate scales; basal pinnae equal to or slightly smaller than adjacent pair, - equilateral, proximal basiscopic pinnules not greatly enlarged; ultimate segments sessile to subsessile, narrowly adnate to costae.
Sporangia: Segment margins slightly recurved, rarely concealing sporangia.
Ecology: Limestone rocky slopes, outcrops, cliffs and in crevices; 984-6234 ft (300--1900 m).
Notes: The lanceolate shape of fronds resemble Cheilanthes, however, this species can be distinguished by fronds which are inconspicuously 2-pinnate, the pinnae appearing lobed and not divided into small segments; the hairs on the top surfaces of pinnae and especially the dense ciliate and stellate scales on the undersides of pinnae that conceal powdery, white farina (small flour-like grains). This species is rare in the US and all specimens examined have been apogamous (reproduces without fertilization) triploids that arose through autopolyploidy (spontaneous duplication of chromosomes).
Ethnobotany: unknown
Etymology: Notholaena is from the Greek nothos, false, and chlaina, a cloak, a reference to the incomplete indusium. Aschenborniana is for Alwin Aschenborn, 1816-1865, 19th century plant collector who found the type specimen in Mexico.
Synonyms: Cheilanthes aschenborniana, Chrysochosma aschenborniana
Editor: FSCoburn 2014
