Notes on the Origin and the Past of the Chlamydospermophyta

Various morphogenetical features, especially those of the fructifications ("flowers" ), as well as the palaeontological documents of the occurrence in the past of the representatives of the Chlamydospermophyta (Ephedra, Gnetum and Welwitschia) are examined and a now conception of their past is suggested. They are considered as evolved nearly along with the Angiosporsms, with which they have no nearer allianccs, representing three quite independent, blind and very narrow evolutionary side lines (detached from different gymnospermous groups; polyphyletic origin), which never became more copiously split into diverse families and genera. From this point of view therefore they are not to be regarded as relic types of some hypothetical ancient, once rather more comprehensive taxons of which various missing links have become extinct. Their past is interpreted like that of several relict pteridospormous groups of the Mesozoic period (Caytoniales, Corystospermales, Lepidospermales [i.e . Peltaspermsles] a.o.), which likewise have never represented any larger taxons.