In botany, an evergreen plant is a plant having leaves all year round. This contrasts with deciduous plants, which completely lose their foliage for part of the year. Leaf persistence in evergreen plants may vary from a few months (with new leaves constantly being grown and old ones shed), to several decades (over thirty years in Great Basin Bristlecone Pine Pinus longaeva ). One additional special case exists in Welwitschia, an African gymnosperm plant which produces only two leaves, which gr… (More on Evergreen)