Ceratopteris Brongn.
Descripción
Rooting in mud or free-floating; rhizomes poorly developed, short-creeping, sparsely and obscurely scaly; fronds clustered, the fertile and sterile strongly dimorphic; sterile blades simple or merely lobed to pinnatifid, or 1–3-pinnate, glabrous, succulent to herbaceous; veins areolate, lacking included veinlets; vegetative buds often present in sinuses of pinnae; fertile blades 2–4-pinnate, erect, taller than the sterile, the blade divisions linear, 1–3 mm wide, the margins inrolled over the sporangia; sori marginal, paraphyses absent; sporangia sessile or nearly so, at the ends of veins; annuli vestigial or well developed with to ca. 70 indurate cells; spores tetrahedral-globose, with ± parallel ridges, lacking equatorial flanges; x=39.A
Forma de vida
Hidrófita libre, Hidrófita enraizadaA
Distribución
México (Country) native and not endemicB
Categoría IUCN
No incluidaC
Categoría NOM-059-SEMARNAT-2010
No incluidaD
Discusión taxonómica
There are three or four species of Ceratopteris in tropical regions, usually in standing or slow-moving water or rooted in mud. The genus has been widely utilized in studies of reproductive biology and fern genetics because of its relatively quick growth and ease of culture.
Affinities of Ceratopteris, often placed in the monotypic family Parkeriaceae, are clearly with the Pteridaceae s.l. Tryon and Tryon (1982) and Kramer (in Kubitzki, 1990), respectively, included Ceratopteris as a tribe Ceratopterideae, or subfamily Ceratopteroideae, within the Pteridaceae. All recent molecular data support inclusion of Ceratopteris with the Pteridaceae s.l. (Gastony & Rollo, 1995, 1998; Hasebe et al., 1995; Pryer et al., 1995), or the breakup of the Pteridaceae into ca. 5 smaller monophyletic families. In all of these phylogenetic topologies, Ceratopteris is the sister group to Acrostichum. However, Ceratopteris is aberrant in the family in the chromosome base number (x=39), in occupying aquatic habitats, in dimorphic fronds, in spore morphology, and in the ill-defined annulus with the large number of weakly indurate cells.
A
Affinities of Ceratopteris, often placed in the monotypic family Parkeriaceae, are clearly with the Pteridaceae s.l. Tryon and Tryon (1982) and Kramer (in Kubitzki, 1990), respectively, included Ceratopteris as a tribe Ceratopterideae, or subfamily Ceratopteroideae, within the Pteridaceae. All recent molecular data support inclusion of Ceratopteris with the Pteridaceae s.l. (Gastony & Rollo, 1995, 1998; Hasebe et al., 1995; Pryer et al., 1995), or the breakup of the Pteridaceae into ca. 5 smaller monophyletic families. In all of these phylogenetic topologies, Ceratopteris is the sister group to Acrostichum. However, Ceratopteris is aberrant in the family in the chromosome base number (x=39), in occupying aquatic habitats, in dimorphic fronds, in spore morphology, and in the ill-defined annulus with the large number of weakly indurate cells.
A