Ceratopteris pteridoides
Description
Plants floating, occasionally rooted in mud; stipes 4–17 mm wide, often inflated or enlarged distally; sterile fronds ca. 8–30 X 5–25 cm; sterile blades mostly simple and palmately 3-lobed or pinnatifid and 5-lobed (occasionally pinnate-pinnatifid at the base), the proximal pinnae (or lobes) opposite or nearly so; buds often present in blade sinuses of actively growing fronds; fertile fronds ca. 15–50 X 8–35 cm, pinnae 4–9 pairs, ascending, proximal pairs often opposite or subopposite; sporangia with annuli absent or vestigial, the indurate cells 0–12(–40); spores 32 per sporangium; 2n=78 (Salv).B
B. Mickel, J. T. & Smith, A. R. 2004: The Pteridophytes of Mexico Vol. 88
Discussion
Lloyd (1974) recognized four species in the genus, three of which were cited from both Guatemala and the United States. Although he cited only one specimen of Ceratopteris from Mexico (Liebmann s.n., US!) and this was identified as a hybrid between C. pteridoides and C. richardii Brongn., we refer all but one recent Mexican collection to C. pteridoides.
Ceratopteris pteridoides has 32 spores per sporangium, stipe width 4–17 mm, sterile blades often simple (palmately or pinnately lobed), sometimes pinnate, and proximal pinnae or segments of sterile blades opposite. Ceratopteris richardii Brongn. (Dict. Class. Hist. Nat. 3: 351. 1823) reputedly has 16 spores per sporangium, stipe width 0.8–6.5(–12) mm, sterile blades pinnate to bipinnate, and proximal pinnae of sterile blades inserted mostly alternately. Tryon and Tryon (1982) treated C. richardii as a synonym of C. thalictroides. Hickok and Klekowski (1974) and Hickok (1977) found that synthesized hybrids between C. pteridoides and C. richardii, both diploids, resulted in 40% viable spores, suggesting that those two species are not completely reproductively isolated. The affinities of C. richardii are still uncertain; Lloyd (1974) thought it intermediate morphologically between C. thalictroides and C. cornuta (P. Beauv.) Lepr., an African species. Should C. richardii prove to be synonymous with C. pteridoides, then the former name has priority.
C
C. Mickel, J. T. & Smith, A. R. 2004: The Pteridophytes of Mexico Vol. 88
Ceratopteris pteridoides has 32 spores per sporangium, stipe width 4–17 mm, sterile blades often simple (palmately or pinnately lobed), sometimes pinnate, and proximal pinnae or segments of sterile blades opposite. Ceratopteris richardii Brongn. (Dict. Class. Hist. Nat. 3: 351. 1823) reputedly has 16 spores per sporangium, stipe width 0.8–6.5(–12) mm, sterile blades pinnate to bipinnate, and proximal pinnae of sterile blades inserted mostly alternately. Tryon and Tryon (1982) treated C. richardii as a synonym of C. thalictroides. Hickok and Klekowski (1974) and Hickok (1977) found that synthesized hybrids between C. pteridoides and C. richardii, both diploids, resulted in 40% viable spores, suggesting that those two species are not completely reproductively isolated. The affinities of C. richardii are still uncertain; Lloyd (1974) thought it intermediate morphologically between C. thalictroides and C. cornuta (P. Beauv.) Lepr., an African species. Should C. richardii prove to be synonymous with C. pteridoides, then the former name has priority.
C
Habitat & Ecology
Floating in marshes, ponds, or in slow-moving rivers or streams.E
E. Mickel, J. T. & Smith, A. R. 2004: The Pteridophytes of Mexico Vol. 88
Specimen
Chis (Breedlove 56074, CAS, ENCB, LL, MEXU, NY). Gro (Lozada P. 926, FCME; Velázquez 740, ENCB). Nay (Téllez 10363, MEXU). Tab (Cowan 2804, CAS, CHAPA, ENCB, MEXU, NY, 2882, CHAPA, ENCB, NY; Haynes 5500, NY; Zamudio 1057, MEXU). Ver (Lot 1625, ENCB, IEB, MEXU; Palacios-Rios 3232, XAL).F
F. Mickel, J. T. & Smith, A. R. 2004: The Pteridophytes of Mexico Vol. 88