Fig. 90.
Fig. 90. Fossil Wood, Abietites Linkii. A Coniferous plant from the Wealden, showing punctated woody tissue and medullary rays.
The flora of the Wealden epoch is characterised in the south of England by the abundance of the fern called Lonchopteris Mantellii, and in Germany by the predominance of the Conifer denominated Abietites Linkii (Fig. 90), and the presence of Araucarites Pippingfordensis, as well as by numerous Cycadaceæ, such as species of Cycadites, Zamites, Pterophyllum, Mantellia, Bucklandia, and a remarkable genus having a fleshy fruit, and related to the ordinary Cycadaceæ as Taxus is to the other Coniferæ, which has been fully described in the Linn. Trans., under the name of Bennettites ([Plate II. Fig. 3]). In the Wealden at Brook Point, Isle of Wight, Cycads have been detected allied to Encephalartos. The fruits of them are described by Carruthers as Cycadeostrobus. He describes the following species:—Cycadeostrobus ovatus ([Plate II. Fig. 1]), C. truncatus, C. tumidus, C. elegans, C. Walkeri, C. sphæricus, in the Oxford clay of Wiltshire; C. primævus in the inferior Oolite at Burcott Wood and Livingston, and C. Brunonis. Mantell states that he has found 40 or 50 fossil cones in the Wealden of England; they belong either to the genus Cycadeostrobus or to the pines mentioned below as occurring in the Wealden. The Wealden fresh-water formation terminates the reign of Gymnosperms. Carruthers gives the following list of the remains of Coniferæ which have been found in the secondary strata of Britain, excluding the Trias:—
Upper Chalk.—Wood in flint nodules.
Upper Greensand.—Foliage and cone of Sequoiites Woodwardii; cone of Pinites oblongus.
Gault.—Cones of Pinites gracilis and P. hexagonus, Sequoiites Gardneri and S. ovalis.
Lower Greensand.—Water-worn and bored pieces of wood; cones of Pinites Benstedi, P. Sussexiensis, and P. Leckenbyi.
Wealden.—Driftwood, foliage of Abietites Linkii; cones of Pinites Dunkeri, P. Mantellii, P. patens, and P. Fittoni, and of Araucaria Pippingfordensis; foliage (and drupes?) of Thuites Kurrianus.
Purbeck.—Fossil forest in situ at Isle of Portland; cone "nearly related to Araucaria excelsa" in the Dirt-bed.