Gymnosperms and angiosperms make up all of the plants classified as seed plants, meaning that they produce pollen grains and seeds. These seeds are all well protected from drying out. However, there are numerous differences between gymnosperms and angiosperms.
The term gymnosperm comes from the Greek gymnos, meaning naked, and sperma, meaning seed, and refers to a type of woody seed plant that has seeds that are enclosed in cones as opposed to fruit. Their wood consists primarily of xylem tissue, and lacks the more rigid tissues found in some flowering plants. Because of this, gymnosperms are classified as “soft” woods and not “hard” woods. There are four groups of gymnosperms: conifers, cycads, ginkgoes, and gnetophytes. The conifers are the familiar pine trees found in most mountainous regions and consist of 575 species. Cycads, once quite plentiful during the Mesozoic era at the time of the dinosaurs, are now in danger of becoming extinct because they grow extremely slowly. Of the ginkgoes, there is only one surviving species, Ginkgo biloba, the maidenhair tree. Gingko trees are resistant to pollution and do well in city parks and along city streets. The last phylum of gymnosperms, Gnetophyta, consists of 70 species divided into three genera that do not resemble each other. The first, Gnetum, occurs in the tropics and consists of trees and climbing vines. The second genus, Ephedra, occurs only in southwestern North America and southeast Asia. The plants of Ephedra are small, shrubs with scaly leaves. The third genus, Welwitschia, lives in the deserts of southwestern Africa and only has two enormous leaves. All of the four phyla of gymnosperms are primarily characterized by seeds that are enclosed in cones.
On the other hand, the term angiosperm comes from the Greek angion, meaning vessel, and sperma, meaning seed, and refers to flowering plants that bear their seeds in fruits. There are more than 240,000 different species of angiosperms, six times the number of species in all other plant groups combined. The angiosperms are divided into two groups: the monocots and the eudicots. The monocots have only one cotyledon, or seed leaf, in their seeds. Eudicots have two cotyledons in their seeds. Monocots are typically herbaceous, have flower parts in threes or multiples of threes, and have a fibrous root system. Eudicots are typically woody or herbaceous, have flower parts in fours or fives, or multiples of fours or fives, and have a taproot system. Regardless of whether they are monocots or eudicots, angiosperms all have flowers that attract animals and insects, which aid in pollination, and produce fruit that is dispersed by animals.
To sum up, the differences between the two major groups of seed plants, gymnosperms and angiosperms, are these: gymnosperms produce seeds in cones, and angiosperms produce flowers which become seeds enclosed in fruit.
