Fossil plants, Vol. 3

"Fossil plants, Vol. 3 : A text-book for students of botany and geology" by Seward is a scientific textbook written in the early 20th century. It concentrates on fossil gymnosperms—especially seed ferns (Pteridospermeae), cycad-like plants, cordaites, and Bennettitales—using comparative anatomy, morphology, and systematics, with frequent reference to living cycads to frame evolutionary interpretations. The volume is aimed at students of botany and geology and is richly illustrated. The opening of the volume sets its scope in a preface that explains the emphasis on gymnosperms and postpones a global survey of past floras, then launches into a detailed primer on living Cycadales to prepare readers for fossil comparisons. This primer covers cycad habit and diversity, distribution, fronds and stems, reproductive structures (dioecious strobili versus the free megasporophylls of Cycas), seed structure with pollen chambers and motile sperm, probable insect pollination, and distinctive anatomy such as manoxylic wood, multiple cambial rings, and girdle leaf-traces; it also outlines the main tribes and genera (Cycas, Zamia, Dioon, Encephalartos, Ceratozamia, Macrozamia, Microcycas, Stangeria, Bowenia). The text then moves into the Pteridosperms with Lyginopteris oldhamia, clarifying nomenclatural history (preferring Lyginopteris over Lyginodendron for certain casts) and summarizing stem anatomy: a large pith, broad secondary xylem with prominent medullary rays, mesarch leaf-trace bundles, and a reticulate cortical stereome, setting the stage for linking stems, fronds, and seeds (Lagenostoma).

Fossil plants, Vol. 3, by A. C. Seward. Republished by OpenStories from Project Gutenberg eBook #76146.