Astrolepis cochisensis |
Pteridaceae |
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Cochise scaly cloakfern, scaly cloak-fern |
brake family, maidenhair fern family |
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Habit | Plants perennial [annual], on rock or terrestrial, of small (rarely large) stature. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Stems | compact; stem scales uniformly tan or somewhat darker near base, to 10 mm, margins ciliate-dentate to entire. |
compact to creeping, branched or unbranched, dictyostelic, bearing hairs and/or scales. |
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Leaves | 7–40 cm. |
monomorphic to dimorphic, circinate or noncircinate in bud. |
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Petioles | usually with persistent scales proximally, lacking spines; vascular bundles 1–several, roundish or crescent-shaped in cross section. |
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Blade(s) | 1-pinnate to pinnate-pinnatifid, pinna pairs 20–50. |
1–6-pinnate, without laminar buds. |
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Pinnae | oblong, largest usually 4–7 mm, entire or asymmetrically lobed, lobes 1–4, broadly rounded, separated by shallow sinuses; abaxial scales completely concealing surface, ovate, usually 0.5–1 mm, ciliate with coarse marginal projections; adaxial scales sparse, deciduous, stellate to coarsely ciliate, mostly circular to elliptic, peltate, body more than 5 cells wide. |
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Veins | pinnate or parallel in ultimate segments of blades, simple or forked, free or infrequently anastomosing in complex patterns. |
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Indusia | (when present) formed by reflexed, recurved, or revolute leaf margin (false indusium). |
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Sori | borne abaxially on veins, often confluent with age and forming a continuous submarginal band, or sporangia densely covering abaxial surface (acrostichoid); receptacle not or only slightly elevated. |
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Sporangia | containing 32 or 64 spores. |
stalk of 2–3 rows of cells; annulus vertical, interrupted by stalk; spores 64 or 32 (rarely 16) per sporangium. |
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Spores | all 1 kind, brown, black, or gray (rarely yellow), globose to globose-tetrahedral or trigonal, occasionally with prominent equatorial ridge, trilete, or trigonal, variously ornamented (usually cristate or rugose). |
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Gametophytes | green, aboveground, obcordate to reniform, sometimes asymmetric, usually glabrous (glandular-farinose in Notholaena); archegonia and antheridia borne on abaxial surface, antheridia 3-celled. |
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Indument | on petioles, rachises, costae, and blades, rarely absent or commonly of hairs, glands, and/or scales, occasionally of white or yellow farina. |
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Astrolepis cochisensis |
Pteridaceae |
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Distribution |
AZ; CA; NM; OK; TX; Mexico
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Worldwide |
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Discussion | Subspecies 3 (3 in the flora). Astrolepis cochisensis is reported to be toxic to sheep (F. P. Mathews 1945). Three cytotypes that occupy different ranges and/or habitats have been identified and are treated here as subspecies. These include a sexual diploid (subsp. chihuahuensis) found on calcareous substrates in the Chihuahuan Desert; an apogamous triploid (subsp. cochisensis), which inhabits primarily calcareous substrates in the Sonoran, Mojavean, and western Chihuahuan deserts; and an apogamous tetraploid (subsp. arizonica), which occupies primarily noncalcareous substrates in southern Arizona. Isozyme analyses suggest that subsp. cochisensis is an autotriploid derivative of the diploid subsp. chihuahuensis (D. M. Benham 1989). Both the isozymes and substrate preferences of subsp. arizonica indicate, however, that it is not a simple autotetraploid and that other taxa remain to be discovered within the Astrolepis cochisensis complex. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Considerable disagreement exists concerning the circumscription and proper name of this family. The taxa comprising the Pteridaceae in this treatment were assigned to the Sinopteridaceae and Pteridaceae by D. B. Lellinger (1985) and were included in five families by R. E. G. Pichi-Sermolli (1977). The broad concept followed here is similar (except for the exclusion of Ceratopteris) to that espoused by R. M. Tryon and A. F. Tryon (1982), who applied the name Pteridaceae to the group. Until very recently, the newer name Adiantaceae was more commonly used. As represented in North America, Pteridaceae comprise three major evolutionary lines (the adiantoids, the pteroids, and the cheilanthoids). Characteristics holding the family together include abaxial (usually submarginal) sori that lack indusia or are protected by a reflexed or revolute leaf margin, spores that are usually globose-tetrahedral and trilete, and chromosome base numbers of 30 or 29 (rarely 27). The xeric-adapted members of the family (particularly the cheilanthoids) have undergone extensive parallel and convergent evolution, and they have frustrated attempts to produce a natural generic classification based on macromorphologic characteristics alone. Although some workers have aggregated species into a few large genera (e.g., J. T. Mickel 1979b), most tend to recognize smaller segregate genera based on a combination of morphologic, chromosomal, and biochemical data. The latter approach seems to provide a more useful, evolutionarily informative classification and is the one adopted here. Aspidotis and Notholaena are maintained here as distinct from Cheilanthes, and three recently described genera (Argyrochosma, Astrolepis, and Pentagramma) have been incorporated into the treatment. The reasons for these changes in generic circumscription are discussed under the individual genera. Genera ca. 40, species ca. 1000 (13 genera, 90 species in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 2, p. 141. | FNA vol. 2, p. 122. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Parent taxa | Pteridaceae > Astrolepis | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sibling taxa | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Synonyms | Notholaena cochisensis, Cheilanthes cochisensis, Cheilanthes sinuata var. cochisensis, Notholaena sinuata var. cochisensis | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Name authority | (Goodding) D. M. Benham & Windham: Amer. Fern J. 82: 57. (1992) | E. D. M. Kirchner | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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