Subphylum Spermopsida

Subphylum Spermopsida

Another great step up the evolutionary ladder is seen in the seed-bearing plants (Spermopsida) which are so well adapted to life on land that they can be found almost everywhere on Earth. More primitive plants reveal their aquatic origins by requiring watery surroundings for at least one stage in their life cycle, the fertilisation of the female egg by the male sperm. With a few odd exceptions, Seed Plants do not have swimming sperm. Also seeds contain their own food supply which makes them well equipped to survive until conditions are right for germination. [CH] {TP}