Astrolepis

D. M. Benham & Windham

Amer. Fern J. 82: 55. 1992.

Common names: Star-scaled cloak ferns
Etymology: Greek astro, star, and lepis, scale, in reference to the starlike scales on the adaxial blade surface
Treatment appears in FNA Volume 2.
 TaxonIllustrator 
FNA2 P20 Cryptogramma-Astrolepis-Notholaena pg 137.jpegAstrolepis cochisensis subsp. cochisensis
Cryptogramma acrostichoides
Notholaena aschenborniana
John Myers
John Myers
John Myers

Plants usually on rock. Stems compact to short-creeping, erect to ascending, sparingly branched; scales tan to chestnut-brown, concolored to weakly bicolored, linear-attenuate, margins ciliate-dentate to entire. Leaves monomorphic, densely clustered, 7–130 cm. Petiole dull chestnut-brown or straw-colored, rounded adaxially, sparsely to densely covered with scales, with 2 vascular-bundles. Blade linear to linear-oblong, 1-pinnate to pinnate-pinnatifid, leathery, abaxially covered with overlapping, lanceolate to ovate, ciliate scales with underlying layer of stellate scales, adaxially sparsely to densely covered with stellate or coarsely ciliate scales, often glabrescent when mature, dull, not striate; rachis straight. Ultimate segments (pinnae) stalked to subsessile, free from axis, ovate, oblong or elongate-deltate, cordate to subcordate or rarely truncate at base, usually more than 4 mm wide; segment margins plane, undifferentiated, not recurved to form false indusia. Veins of ultimate segments obscure, pinnately branched and divergent distally. False indusium absent. Sporangia scattered along veins near pinna margins (often clustered near notches between pinna lobes), containing 32 or 64 spores, not intermixed with farina-producing glands. Spores light to dark-brown, tetrahedral-globose, rugose, lacking prominent equatorial-ridge. Gametophytes glabrous. x = 29.

Distribution

North America, Mexico, West Indies, Central America, South America

Discussion

The species of Astrolepis have traditionally been assigned to either Notholaena (R. M. Tryon 1956) or Cheilanthes (J. T. Mickel 1979b; R. M. Tryon and A. F. Tryon 1982). Recent biosystematic analyses by D. M. Benham and M. D. Windham (1992) indicate, however, that the star-scaled cloak ferns form a distinctive, monophyletic group worthy of generic recognition. The combination of a chromosome base number of x = 29, pinnate leaves, two vascular bundles in the petioles, unique stellate or coarsely ciliate scales on the adaxial blade surface, and other characteristics separate Astrolepis from related genera.

Species ca. 8 (4 in the flora).

Key

1 Largest pinnae usually 4–7 mm; most adaxial scales circular to elliptic, peltate; abaxial scales ovate, usually 0.5–1 mm. Astrolepis cochisensis
1 Largest pinnae usually 7–35 mm; most adaxial scales elongate, attached at their base; abaxial scales lanceolate, 1–1.5 mm. > 2
2 Adaxial scales dense, usually persistent; largest pinnae asymmetrically lobed or entire; body of adaxial pinna scales 5–7 cells wide. Astrolepis integerrima
2 Adaxial scales sparse, often deciduous; largest pinnae usually symmetrically lobed; body of adaxial pinna scales 1–4 cells wide. > 3
3 Adaxial pinna surface sparsely scaly, at least some scales persistent; body of adaxial scales 2–4 cells wide; abaxial scales ciliate with coarse marginal projections; pinnae shallowly lobed, lobes usually broadly rounded. Astrolepis windhamii
3 Adaxial pinna surface sparsely scaly to glabrescent, most scales deciduous with age; body of adaxial scales 1–2 cells wide; abaxial scales ciliate-dentate with delicate marginal projections; pinnae usually deeply lobed, lobes often acute. Astrolepis sinuata
... more about "Astrolepis"
Dale M. Benham +  and Michael D. Windham +
D. M. Benham & Windham +
glabrescent +
linear +  and linear-oblong 1-pinnate +
Star-scaled cloak ferns +
North America +, Mexico +, West Indies +, Central America +  and South America +
Greek astro, star, and lepis, scale, in reference to the starlike scales on the adaxial blade surface +
yellow +  and white +
obcordate;reniform +
monomorphic +
recurved +  and reflexed +
noncircinate +  and circinate +
7 cm70 mm <br />0.07 m <br /> (130 cm1,300 mm <br />1.3 m <br />) +
ciliate-dentate;entire +
straw-colored;chestnut-brown;dull +
Amer. Fern J. +
benham1989a +, benham1992a +, benham1992b +, hevly1965a +  and tryon1956a +
overlapping +
tan;chestnut-brown concolored +
persistent +
lanceolate +  and ovate +
light +  and dark-brown +
1 +, 32 +  and 64 +
tetrahedral-globose +
erect +  and ascending +
Astrolepis +
Pteridaceae +
crescent--shaped +  and roundish +