The sporophyte in this group, however, became parasitically dependent upon the gametophyte and correspondingly reduced to a single fertile telome (Fig.
The higher land plants evolved from the telome trusses of the primitive forms along three parallel lines, as indicated in the following table: Primitive Land Plants Lycopsida Sphenopsida Pteropsida Examples Selaginella Equisetum Phanerogams Lycopodium Ferns Lepidophyta Transitional Protolepido- Hyeniales Protopteridales Groups dendrales
Reduction of a telome system may lead to the formation of a single needle-like leaf (Fig.
On this basis a few selected fields will be explored to see whether morphological facts have been clarified or may be interpreted usefully in the light of the telome theory.
The telome theory offers one explanation for the nature of the aerial portion of the plant body of the Ophioglossaceae.
The anatomy of some species of the Medutlosaceae supports certain aspects of the telome theory.
The telome theory is also involved in the interpretation of the nature of the plant body in the coenopterid ferns.
The most extensive and fruitful application of the telome concept is found in the studies of Dr.
Each organ was a cruciately dichotomized terminal telome system carrying two or more pendent ovules at the apex (Fig.
The ovule represents a single fertile telome which had attained its terminal position after a process of overtopping.
One of the most clearly defined phylogenetic relationships involving the telome concept was worked out by Florin (1949) between the Lower Permian Trichopitys heteromorpha and the living Ginkgo biloba.
The telome theory, largely founded upon paleobotanical evidence, has been accepted as a working hypothesis by many morphologists and paleobotanists concerned with vascular plants other than the angiosperms.