They have naked seeds, in contrast to the seeds or ovules offlowering plants (angiosperms) which are enclosed during pollination. Gymnosperm seeds develop either on the surface of scale- or leaf-like appendages ofcones, or at the end of short stalks (Ginkgo).[2]
Fossil gymnosperms include many that do not belong to the four modern groups, including the so-called "seed ferns" (Pteridosperms) and the "cycadeoids" (Bennettitales). Most of the Gymnosperms becameextinct in theCenozoic era (from 65 million years ago to present day).[4]
Some genera havemycorrhiza, fungal associations with roots (Pinus). In some others (Cycas) small specialised roots have nitrogen-fixingcyanobacteria.
↑The term comes from theGreek word (γυμνός) for "naked seed",gymnospermos.
↑Anderson, Anderson & Cleal 2007. Brief history of the gymnosperms: classification, biodiversity, phytogeography and ecology. Strelitzia.20 SANBI. p280.ISBN 978-1-919976-39-6
