A revision of the English Wealden Flora, III: Czekanowskiales, Ginkgoales & allied Coniferales
Eleven gymnosperm leaf species are identified and described from the English Wealden flora, attributed to the orders Czekanowskiales. Ginkgoales and needle-leaved Coniferales. All occur as fragments in the “plant debris beds” which are common throughout the Wealden succession in East Sussex. Dorset and the Isle of Wight. Two new species assigned to the Czekanowskiales are placed in the genera Czekanowskia Heer and Phoenicopus Heer; three new species assigned to the Ginkgoales are placed in the form-genus Ginkgoites Seward; an ovule containing monosulcate pollen grains, associated with one of the Ginkgoites leaves is described and illustrated. Needle-leaved conifers of uncertain family attribution comprise two species assigned to the genus Pseudotorellia Florin, one species to Sciadopityoides Sveshnikova. The shoot species Sulcatocladus robustus Watson & Harrison is known to be attributable to the leaf species Pseudotorellia linkii (Römer); a second species of Sulcatocladus Watson & Harrison is attributed to the new species of Sciadopityoides. A leaf species with stomata in two grooves is referred to the form-genus Torreyites Seward and tentatively to the family Taxaceae. The Czekanowskiales are recorded from the Lower Cretaceous of western Europe for the first time and the palaeoecological implications of these additions to the English Wealden flora are discussed.