Gymnosperms are plants that produce seeds but do not develop a flower or fruit. The name comes from Greek words and means naked seed. Gymnosperm seeds attach to the upper surfaces of exposed scales. Usually these scales bearing seeds are grouped together in cones. The leaves are usually needle-like and stay green year round. They are wind pollinated.
There are four classes of Gymnosperms: conifers, cycads, ginkgo, and gnetophytes. They make up the oldest living tress, the most massive trees, and the tallest living trees.
Angiosperms or anthophytes are plants that produce seeds, flowers, and fruit. The name means covered seed. The flower in an angiosperm is a reproductive structure. Seeds develop when pollen grains are transferred to the tips of the pistils or female structures of the flower. They are wind, bird, and insect pollinated.
Some flowers and insects have a symbiotic or mutual relationship. The flower contains both the male and female sex organs. The seed bearing parts of the flower ripen into fruits. The fruits often contain tissues that attract animals through bright colors, fragrance, nutrients, or a combination of all three of these.
Angiosperms have broad leaves that change color and die in the autumn. Angiosperms that are dependent on birds for pollination usually have brightly colored flowers to attract the birds. Red flowers are common in Angiosperms dependent on birds for pollination.
Some Angiosperms and insects have dependent relationships. Figs are a tropical shrub that produces fruit. Fig wasps pollinate the fig flowers. The wasp pupa can only develop within the fig flowers and the figs can only be pollinated by the fig wasps.
The fig is unusual in that the flower is contained within the fig plant. That is why the wasp is so critical to pollination. No other insect can see the fig flowers. No other insect is small enough to bore into the fig.
Many fruit trees are dependent on bees to pollinate the flowers that will grow into seeds and fruit.
Gymnosperms are different than angiosperms because they adapted to climate conditions. Needle-like leaves conserve water by slowing down evaporation, a very successful adaptation in temperate and cold climates.
Angiosperms are more developed on the evolutionary scale than gymnosperms. Angiosperms are the most successful and advanced plants on the earth. The fruit adaptation allows for wide dispersal of the seeds by animals that eat the fruits. Some Angiosperms are dependent on the animals to disperse seeds to grow new plants.
Some species such as figs will not grow beneath an established shrub or tree. Humans eat apples, peaches, melons, nuts, grains, peppers, tomatoes, and cucumbers.
