Plant terminology can be quite confusing, especially with words like gymnosperms and pteridophytes. The names don’t really convey any information about what they both refer to, at least for most people. What these two groups are, and the differences between them, will be explained.
One of the two groups of plants that have seeds is the gymnosperms. In fact the name gymnosperm means ‘naked seed’, and this describes the plant perfectly as the seeds are not part of a fruit but grow on their own, exposed or unprotected. This seed is commonly, in most of the gymnosperm plants, in the form of a cone and often referred to as a ‘pine cone’. This group features some of the most ancient plants among the seed plants and includes conifers (pines, spruces, and firs for example) as well as many other trees, shrubs, and even a few vine-like species of plants. These plants can be very useful for their timber and some have medicinal uses as well.
The pteridophytes are a very important group of plants that are considered the first true land plants. They are significantly older than the other types of plants and date back about 380 million years. Scientists know this because of fossil evidence of these plants. These plants are not seed plants, relying instead on spores to spread and reproduce. Pteriodophytes are actually the precursor to the seed plants and over time the seed plants evolved from them. This group includes ferns, different types of mosses and other plants. Sometimes the group name is used just to describe ferns, but this is incorrect.
What are the differences between them?
Though gymnosperms evolved from pteridophytes, they are quite different from each other. The plant bodies of gymnosperms are typically much larger than the pteridophytes. All gymnosperms are also heterosporous, meaning that they produce two different kinds of spores, while pteridophytes may be both heterosporous and homosporous. Fertilization with a pollen tube, as well as pollination, are not present in pteridophytes but are in gymnosperms. Gymnosperms can also have secondary growth of the plant while pteridophytes don’t. The final difference between the two groups is in the roots of both types of plants. Gymnosperms have a tap root while the pteridophytes do not. The tap root grows down vertically into soil and other roots sprout from it in horizontal or nearly horizontal directions. The roots of the pteridophytes grow randomly or by chance and follow no specific pattern or system like the tap root of gymnosperms.
Rajan, S. Sundara. Introduction to Modern Botany