Astrolepis (star-scaled cloak fern) species were, until 1992 (Benham and Windham), classified under the broad "cloak" of Cheilanthes and/or Notholaena and, more specifically, traditionally grouped as Cheilanthes or Notholaena sinuata or varieties thereof. The upper pinnae surfaces have a smattering of the namesake starry hairs, and the lower surfaces are crowded with a thick mat of matching silver to tan starry scales. Veins are free, forking, and barely visible. There are two vascular bundles as opposed to the singular ones in Cheilanthes and Notholaena. Sori without indusia are scattered along the veins and obscured (to the dismay of propagators) by the hairy mass. Many species are apogamous. The genus does not have inrolled pinnae margins.
The name is derived from the Greek astro, star, and lepis, scale, and captures the botanical personality of this star-studded genus. The six to eight evergreen species are exclusively New World. In their native sites, they are accustomed to periodic summer monsoons but dry winters. In cultivation they share a preference for well-drained, gravelly soil, and garden or artificial sites offering winter wet protection (under overhanging eaves or in the specialized climate of an alpine house). They are cultivated in Zones 7 to 9 and are not as temperamental as some of the other xerics.
Astrolepis beitelii (after U.S. botanist Joe Beitel, 1951-1991), Beitel's cloak fern, synonym Cheilanthes beitelii, has once-pinnate, strongly vertical, clustered, 8- to 20-in. (20-to 50-cm), linear blades. The lobed, evergreen, bluish pinnae have linear hairs on the upper surface and brown to silver scales below. The rosy stipe with a mixture of whitish scales and hairs is one-fourth of the frond length. This species is very closely related to A. sinuata and is separated (barely) based on having broad pinnae that can be more than 1 in. (2.5 cm) long and long linear hairs rather than starry hairs on the upper pinnae surface. Mickel and Smith (2004) now classify this as A. laevis, but sentiment, rather than science, compels me to continue to honor my late friend, Joe. This fern prefers warm Zone 9 rock garden sites.
Astrolepis cochisensis (after Cochise County, Arizona), Cochise's cloak fern, synonym Notholaena cochisensis, is less than a foot (30 cm) tall with upright, narrow, once-pinnate blades that taper at both ends. Up to 40 pairs of entire to slightly lobed V4 in. (6 mm) evergreen pinnae crowd the fronds. The pinnae have circular whitish scales on the upper surface and rusty scales below. The stipes, pressed with toothy scales, are one-sixth to one-fourth of the frond length. Found in limestone crevices, in the extreme southwestern United States and adjacent Mexico, it can be coaxed along in limey grit by specialists in Zones 8 and 9. It is reputed to be toxic to sheep should you have any wandering around the garden. Apogamous.
Astrolepis integerrima (undivided), synonyms Notholaena sinuata var. integerrima, Cheilanthes integerrima, and N. integerrima, is another cousin of Astrolepis sinuata differing in having asymmetrical pinnae with their upper surfaces garnished with persistent scales. It is a narrowly upright, once-pinnate evergreen with up to 40 pairs of pinnae and is native to rocky crevices, often of limestone, in the U.S. Southwest. Grow these species side by side for conversation and education in well-drained grit away from winter wet in Zones 7 to 10. Apogamous.
Astrolepis sinuata (bend, wave), wavy cloak fern, synonyms Cheilanthes sinuata and Notholaena sinuata, is a variable species with evergreen fronds softly dressed in xeric characteristic, small silver stellate hairs above and masses of protective, whitish scales and hairs below. The stellate hairs rather than linear hairs, as well as pinnae of 1 in. (2.5 cm) or less, separate this species from the extremely similar A. beitelii. The stipes, crowded with hairs and scales, are pale green with dark bases in infancy and progress to shades of rust as they mature. Once-pinnate, 18-in. (45-cm) blades stand upright in dense clusters with 20 or more pairs of chubby, lobed pinnae looking like miniature cookie-cutter holly leaves. Sori without indusia gather in batches along the veins towards the margins. In typical xeric fashion this fern inhabits rocky crevices and slopes sometimes on limestone. It makes an elegant, conversational element, given a blessing of gritty compost and shelter from
Astrolepis integerrima in the garden of xeric specialist David Schwartz. Photo by David Schwartz.
wet winter slop, in Zones 7 to 9. Limestone is not necessary. A glance at history shows the epithet sinuata in associated synonymy with all of those species now classified as Astrolepis. It has to be the figurative grandparent of all cloak ferns. Surprisingly, it also makes a fine houseplant (Stuart, pers. comm.). Apogamous.
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