Filicinean sentence example
- The line of descent of recent cycads is comparatively clear in so far as they have undoubted affinity with Palaeozoic plants which combined cycadean and filicinean features; but opinion is much more divided as to the nature of the phylum from which the conifers are derived.
- From an evolutionary point of view, it is of interest to note the occurrence of filicinean and cycadean characters in the maidenhair tree.
- Heterangium shows, on the whole, a decided preponderance of Filicinean vegetative characters, though in the leaf-traces and the secondary tissues the Cycads are approached.
- The Upper Carboniferous and Permian plants may be grouped together as constituting a Permo-Carboniferous flora characterized by an abundance of arborescent Vascular Cryptogams and of an extinct class of plants to which the name Pteridosperms has recently been assigned - plants exhibiting a combination of Cycadean and filicinean characters and distinguished by the production of true gymnospermous seeds of a complex type.
- Since about 1895 this branch has been most actively pursued in England, where the work of Boodle and of Gwynne-Vaughan especially on Ferns) has been the most important, leading to a coherent theory of the evolution of the vascular system in these plants (Tansley, Evolution of the Filicinean Vascular System, Cambridge, 1908); and in America, where Jeffrey has published important papers on the morphology of the vascular tissues of the various groups of Pteridophytes and Phanerogams and has sought to express his conclusions in a general morphological theory with appropriate terminology.Advertisement
- It is needless to discuss at length the origin of the Gymnosperms. The two views which find most favour in regard to the Coniferales and Cycadophyta are: (I) that both have been derived from remote filicinean ancestors; (2) that the cycads are the descendants of a fern-like stock, while conifers have been evolved from lycopodiaceous ancestors.