n p singh r c srivastava (1 Ergebnisse)

Soft cover. Zustand: As New. Contents: Introduction. Enumeration. 1. Araucariaceae. 2. Cupressaceae. 3. Cycadaceae. 4. Ephedraceae. 5. Ginkgoaceae. 6. Gnetaceae. 7. Pinaceae. 8. Podocarpaceae. 9. Taxaceae. 10. Taxodiaceae. 11. Welwitschiaceae. 12. Zamiaceae. References. Index to botanical Names. From the introduction: The word 'gymnosperm' derived from the Greek word gymnospermos meaning naked seeds, after the unenclosed condition of their seeds otherwise known as ovules in their unfertilized state. Gymnosperms are that group of seed plants where an ovule is not enclosed in carpel, unlike angiosperms. The ovule instead forms a leaf-like structure homologous to a leaf, or on a scale or megasporophyII homologous to a shoot or on the apex of a dwarf shoot. Megasporophylls are frequently aggregated into compound structures that are often cone-shaped hence the colloquial name for some of the group, conifers.