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Old 01-27-2008, 06:37 PM   #12 (permalink)
zoosey
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Just a few thoughts on the Abstract. It states:

"Moreover, further investigation based on the trnL-F (340 bp) intergenic spacer from 31 Lomariopsis species suggested L. lineata might be the closest species to the mysterious gametophyte. The trnL-F sequences from L. lineata and the mysterious gametophyte show 97.6% identity and share an 8-base-long gap."

Im not a botanist, and this might be a silly question, but do "might be the closest species to" and "97.6% identity" mean that the gametophyte is infact L. Lineata?

Also, if "No associated sporophyte has been discovered", What is
http://www.nbids.org/share/PhotoGall...20lineata.html

And if no L. lineata sporophyte has been discovered, and Subwassertang is L. lineata,than we shouldnt have a description of L. lineata's pinnae and spores:
"Upper surface of fertile pinnae 3 - 6 ( - 10) mm wide; spores with an ample folded perispore L. lineata"
http://www.anbg.gov.au/fern/taxa/lomariopsis.html

L. lineata distribution:
"L. lineata (C. Presl) Holttum: s. Thailand , Myanmar , s. Vietnam , Malaya , Java, Borneo , Philippines , w. New Guinea ."
http://www.nybg.org/botany/rmoran/range.htm

In regards to vegetative growth of fern gametophytes:
"Perhaps the most surprising examples of vegetative propagation are those found in primarily tropical genera that have apparently spread and remained in the temperate zones by gametophytic gemmae. Members of three families---Hymenophyllaceae, Grammitidaceae, and Vittariaceae---occur in the Appalachian region as far north as New England, but they often appear only as gametophytes that may produce extensive colonies from the minute, one- or few-celled propagules (D.R. Farrar 1967, 1985). The gametophytes themselves are simple algalike filaments or ribbons, easily confused with green algae or liverworts. These gametophytes have few or no gametangia, and they are apparently adapted to growing only in shaded, humid, bryophytic habitats, mainly in rock crevices and grottoes. They normally produce no sporophytes at all and are the only representatives of their respective families
in the floras of a number of states. In this flora we key them out alongside typical sporophytic members of their genera."
http://nefern.info/jpgs/notaxa/WHWAGNER.HTM

Anyone up for the search for the North American Subwassertang? =D

Also:
"Vegetative reproduction by the gametophyte generation has allowed a number of fern species to persist beyond their normal geographic range. In at least two of these, Trichomanes and Vittaria in the eastern United States, the sporophyte stage of the life cycle has been eliminated completely, perhaps for ten million years or more. Despite this long period of reliance on vegetative reproduction, genetic diversity in the Appalachian Vittaria gametophytes, as measured by starch gel enzyme electrophoresis, remains comparable to that of sexual plants, although it is largely partitioned into monomorphic populations. Widely separated populations are not particularly divergent; the taxon as a whole appears equally as cohesive as sexual species, suggesting that factors other than gene flow are responsible
for long term maintenance of species integrity. The Appalachian Vittaria gametophytes and similarly derived taxa merit recognition as distinct species."
http://links.jstor.org/sici?sici=036...OR-enlargePage

From what Ive read so far, it would seem that referring to Subwassertang as L. lineata would be false. I don't even think "Loma fern" would be appropriate since Lomariopsidaceae hosts at least 800 species including Bolbitus, and Lomariopsis 45 species. Lomariopsis 'Süßwassertang' would probably be the most appropriate. If there is any new information Im overlooking regarding the taxonomy of Subwassertang or any threads Ive missed, please let me know! Sorry if any of that was redundant.

Sean
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