Formation and ultrastructure of a complex, multilayered wall around the oospore of Chara and Lamprothamnium (Characeae).
The oosporangium of the Characeae (Chlorophyta, Charales).
Much of the current difficulty with charophyte identification was engendered by Wood's (1965) treatment of the Characeae
in which numerous taxa were lumped under individual species and assigned subspecific ranks.
Species belonging to the family Characeae are typical of oligotrophic environments, in which water transparency is higher and the density of phytoplankton is lower (Kiersch, Muhleck, & Gunkel, 2004).
Biomass (g/[m.sup.2]) of families and biological forms (BF) in Penha reservoir (city of Joao Pessoa, Northeast Brazil) BF Dry season Voucher Families Oct 09 Dec 09 Feb 10 Characeae Chara sp.
Imahori, A Revision of the Characeae
, Cramer, Weinheim, Germany, 1965.
in Mart.) Mitt.- Meteorium widgrenianum (C.Mull.) Mitt.- Meteoriopsis characeae
At the same time Cristatella mucedo statoblasts appear in the sediment record and the abundance of Characeae
oospores rises considerably.
A small number of Characeae
oogonia is characteristic of this PMA.
Nota floristica: los Characeae
del Noroeste de la Isla de Menorca.
* Nitella flexilis (L.) Agardh.
As the results of plant macrofossil analysis mainly reflect species from local vegetation, it is not surprising that most of the seeds and vegetative parts belonged to the aquatic species: Ranunculus sect Batrachium, Characeae
, Equisetum sp., Potamogeton sp., and different aquatic mosses (Drepanocladus sp., Scorpidium sp.).
Similarly, 10 species of Characeae
were found in the Pantanal, which is attributed to the alkaline and brackish waters in the Southwestern Pantanal (Bueno 1993, Pott & Pott 1997), but only two were identified in the Parana floodplain, where acid soils predominate and charophytes do not thrive.
The families with the highest number of species were Poaceae (14 taxa), Cyperaceae and Polygonaceae (seven taxa each) and Characeae
, Araceae, Hydrocharitaceae, Onagraceae (four taxa each).
Ademas, se utilizaron las descripciones especificas para las especies de Characeae
(Wood y Imahori 1964, 1965, Guerlesquin 1981), Azollaceae (Slocum y Robinson 1997), Hydrocharitaceae (Holm-Nielson y Haynes 1986), Potamogetanaceae (Holm-Nielson y Haynes 1986a) y Pontederiaceae (Horn 1987).