Mexican holly fern [Greek phaneros, free, and phlebium, vein, for the nonanastomosing venation found in the type species, P. nobilis ]

George Yatskievych

Plants terrestrial, less commonly on rock. Stems short-creeping to erect, stolons absent. Leaves monomorphic, evergreen. Petiole shorter than or ± equaling length of blade, base not swollen; vascular bundles more than 3, arranged in an arc, ± round in cross section. Blade ovate-lanceolate, 1-pinnate, with a ± similar apical pinna, papery. Pinnae not articulate to rachis, segment margins serrulate to spinulose; proximal pinnae largest or nearly so, short-petiolulate, ± equilateral or inequilateral with acroscopic lobe; costae adaxially grooved, grooves continuous from rachis to costae; indument of filiform scales on costae and veins abaxially, ± glabrous adaxially. Veins free [anastomosing], forked. Sori in 2 or more rows between midrib and margin, round; indusia persistent or caducous [absent]. Spores brown, with inflated folds or wings. x = 41.

Species 8 (2 in the flora): North America, Mexico, Central America, n South America, West Indies in Hispaniola.

Phanerophlebia has sometimes been included in Cyrtomium , which it resembles superficially. As with that genus, Phanerophlebia might better be considered a subgenus of Polystichum , from which it is poorly differentiated morphologically. Elsewhere, some species have bicolored stem scales, netted venation, and/or lack indusia.

SELECTED REFERENCES

Maxon, W. R. 1912. Notes on the North American species of Phanerophlebia. Bull. Torrey Bot. Club 39: 23--28. Underwood, L. M. 1899. North American ferns---II. The genus Phanerophlebia. Bull. Torrey Bot. Club 26: 205--216.