Barghoorn, Elso S. Department of Biology and Botanical Museum, Harvard University, Cambridge, Massachusetts.
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An incompletely known and poorly defined group of vascular plants whose geologic range extends from the Upper Carboniferous to Triassic. Their taxonomic status and position in the plant kingdom are uncertain since morphological evidence (because of the paucity of the fossil record) does not make it possible to place the group confidently in any recognized major subdivision of the vascular plants. A rather heterogeneous assemblage of foliar and vegetative organs assignable to fairly well-defined genera have been placed in the group, thus somewhat forcing the concept that these parts constitute a natural order of vascular plants. Internal anatomy is unknown, with exception of the possible noeggerathialean genus Sphenostrobus. Noeggerathialean genera include Noeggerathia, Noeggerathiostrobus, Tingia, Tingiostachya, and Discinites. The reproductive organs are strobiloid, with whorled organization, and vary from homosporous to heterosporous. In Discinites, the number of megaspores may range from 1 to 16 per sporangium. Foliar organs vary from nonarticulate and fernlike to anisophyllous four-ranked fronds. The Noeggerathiales have been proposed in the evolutionary scheme for vascular plants. See also: Paleobotany; Plant kingdom
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