Gymnosperms: characteristics, classification and examples of species - science - 2023



The gymnospermsthey are a group of vascular plants that have "bare" seeds, but do not produce flowers. Like angiosperms, this group of plants belongs to the "spermatophytes" or higher plants.

Gymnosperms are considered by many botanists to represent a sister group to angiosperms (flowering plants) and that much of the current knowledge of the latter group is due to studies concerning gymnosperms.

According to fossil evidence and bioinformatic analysis, gymnosperms and angiosperms diverged about 300 to 360 million years ago, during the Carboniferous, one of the Paleozoic periods. Although there are currently only about 1000 species, during the Mesozoic these were the predominant forms of plant life.

This group includes the largest plants of the entire plant kingdom, such as members of the species Sequoia sempervirens (over 150 m high) and gender Metasequoia (exceeding 100 meters).

Within the group of gymnosperms are plants as well known as pines (conifers), cycads and ginkgos, among others.

Gymnosperm characteristics

It is believed that there are representative groups of gymnosperms that have not varied in more than 100 million years, that is, that they retain multiple ancestral characteristics. In addition, they are very slow growing plants with great longevity.


These plants are distributed on all continents, with the exception of Antarctica. About two-thirds of all gymnosperms in the biosphere are conifers, which make up more than 35% of the world's forests, especially in the more temperate zones.


All gymnosperms are woody and perennial plants with abundant secondary growth. Its body is divided (although it represents a single unit) into stem, roots and leaves. They differ from other plants in that the plant body is the sporophyte or the asexual generation, which is the one that predominates throughout the life of the plant.

They have stems and roots with abundant secondary growth, a fact that is of particular importance in the group of conifers. The relationship between the different tissue areas of the stems (bark, vascular cambium, wood or log (xylem) and pith) varies according to the species.

Water transport

Regarding the transport of water in gymnosperms, these differ from angiosperms in that their xylem is composed only of tracheid cells (which implies an inefficient transport capacity), while in angiosperms there are both tracheids and vessels.

The hydric conduction characteristics of gymnosperms are related to the type of leaf that these plants present, which can be acicular (on short branches) or large “palm” type, but small in number.


One of the main characteristics of gymnosperms, although not the only one that defines them as a group, is the absence of flowers and the production of "naked" seeds. These are structures where the ovules and seeds are exposed on the surface of sporophylls or other similar structures, and not enclosed in a protective and nutritive layer.

The fertilization of the ovum that is contained in the female gametophyte of gymnosperms occurs thanks to the passive transport by the wind (anemophile) of the pollen grains or of the complete male gametophyte until the proximity of the egg cell (pollination).

Many gymnosperms are monoecious (female and male gametophytes are on the same plant), others are dioecious (female and male reproductive structures on separate plants).

The reproductive structures of each sex are grouped into unisexual strobili, however, some species only have male strobili. A strobilus is a set of sporophils that produce sporangia.

Microsporophils produce macrosporangia-producing macrosporangia (female gametes), while microsporophylls produce microsporangia, responsible for the meiotic production of pollen grains (male gametes).

Classification of gymnosperms

The group of gymnosperm plants represents the five main lineages of seed plants and is divided into four subclasses, grouped within the class Equisetopsida, and known as:

- Ginkgoidae: with a species existing today.

- Cycadidae: with 297-331 species divided into 10 genera. They are typically from tropical American and Asian regions.

- Pinidae: with 614 species divided into 69 genera. These plants are characteristic of the temperate regions of the northern and southern hemispheres.

- Gnetidae: with 80-100 species, divided into 3 genera.

Among these four subclasses, gymnosperms number about 12 families, 83 genera, and about 1000 species.

A curious fact is that, among these 83 genera, 34 of them are monotypic, that is, they include a single species; 22 are composed of between 2 and 5 species and only 3 genera have almost 100 species, which are the genus Cycas, the gender Pinus and gender Podocarpus.


The most extensive lineage of the gymnosperms group is, without a doubt, that of conifers, which is divided into 7 families (although this has been the subject of discussion by many plant systematists) these are:

- Taxaceae

- Podocarpaceae

- Araucariaceae

- Cephalotaxaceae

- Pinaceae

- Taxodiaceae

- Cupressaceae


The group of gnetophytes (subclass Gnetidae) is made up of three families, all made up of a single genus, namely:

- Ephedraceae

- Gnetaceae

- Welwitschiaceae


The classification of cycads has been quite controversial, however, relatively recent publications have recognized that this group is divided into two families, which together add up to 10 genera:

- Cycadaceae

- Zamiaceae

Examples of gymnosperm species

Gymnosperms are a very important group, not only from an ecological point of view but also economically, since in addition to functioning in the earth's carbon cycles, they are an important source of resins, wood, and even drugs and food.


An indisputable example of outstanding gymnosperms is that of the sequoias, belonging to the Taxodiaceae family, of conifers. The sequoias are currently restricted to the state of California, in the United States of North America, and the two existing species are known for their large wingspan, as their average height is more than 100 meters long.

Pine trees

Pine trees also represent one of the most important and best known groups within gymnosperms, since they not only form the most extensive forests on the planet, but also have different industrial uses and are intensively exploited by man for the extraction of wood, production of paper and the obtaining of resins, for example.

Ginkgo biloba

One particular species of gymnosperm, Ginkgo biloba, is also well known within this group. This is the only species of the only genus in the Gingkoidae subclass and is believed to be the oldest representative of all spermatophyte plants living today.


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