HORTICULTURE

Detailed explanation-1: -Gymnosperms. The term gymnosperm (“naked seeds”) represents four extant divisions of vascular plants whose ovules (seeds) are exposed on the surface of cone scales. The cone-bearing gymnosperms are among the largest and oldest living organisms in the world. They dominated the landscape about 200 million years ago.

Detailed explanation-2: -Furthermore, gymnosperms produce two different types of cones, namely, large female cones and small male cones. Four groups of gymnosperms are known: CYCADOPHYTA: 100 cycad species (cycad, sago palm) GINKGOPHYTA: 1 plant species (ginkgo) GNETOPHYTA: e.g., ephedra.

Detailed explanation-3: -By far the largest group of living gymnosperms are the conifers (pines, cypresses, and relatives), followed by cycads, gnetophytes (Gnetum, Ephedra and Welwitschia), and Ginkgo biloba (a single living species).

Detailed explanation-4: -Gymnosperms are heterosporous seed plants that produce naked seeds. They appeared in the Carboniferous period (359–299 million years ago) and were the dominant plant life during the Mesozoic era (251–65.5 million years ago).