Monographs Details: Llavea
Authority: Mickel, John T. & Beitel, Joseph M. 1988. Pteridophyte Flora of Oaxaca, Mexico. Mem. New York Bot. Gard. 46: 1-580.
Description:Genus Description - Terrestrial or epipetric; rhizome stout, horizontal; rhizome scales mostly black at rhizome to stramineous on stipe base; fronds hemidimorphic, bi- to tripinnate, glabrous; veins free; sterile segments ovate with truncate to narrowly cuneate bases, 8-12 mm wide; fertile in terminal third of the blade, fertile segments constricted, linear, 1.5-2 mm wide, margin inrolled, covering the sori, which are slightly elongate along the veins; indusium modified, glandular hairs on inside surface of indusium; spores tetrahedral-globose.
Discussion:Type and only species: Llavea cordifolia Lagasca.
Ceratodactylis J. Smith in Hooker, Gen. fil., t. 36. 1840. Type: Ceratodactylis osmundoides Hooker [=Llavea cordifolia Lagasca].
Botryogramme Fée, Mém. foug. 5: 166. 1852. Type: Botryogramme karwinskii (Kunze) Fée [=Allosorus karwinskii Kunze, = Llavea cordifolia Lagasca].
Llavea is a monotypic genus, the one species occurring in Mexico and Guatemala. Copeland (1947) regarded it as a derivative of Pellaea, but Try on and Tryon (1982) found little support for this hypothesis, instead seeing some distant relationship to Lygodium. Llavea is distinct by its hemidimorphic fronds, recurved margin on the fertile segments, the elliptic sterile segments, and the large, bright yellow to black rhizome scales.