Seed plants come in two great groups, and the difference between them is easier to see than it sounds. Crack open a peach and the seed sits inside the flesh. Pick a seed off a pine cone and nothing wraps it at all.
Angiosperms are the flowering plants, and gymnosperms are the cone bearers and their relatives. Both make seeds, and both use pollen. This guide sets them side by side, feature by feature.
The Ovary Makes the Difference
Seeds Inside, Seeds in the Open
In an angiosperm, the ovules sit inside an ovary, which is part of a carpel. After fertilization the ovule becomes a seed, and the ovary usually becomes the fruit around it.
In a gymnosperm, the ovules are not enclosed in an ovary. They sit on the surface of cone scales or on a stalk. The name says as much: gymnosperm means "naked seed".
Careful with that phrase. Not every gymnosperm ovule is completely bare. In the gnetophytes the ovule can be partly enclosed by surrounding tissue. That is still not the same as an ovary and a fruit.
What Counts as a Fruit
In botany a fruit is a mature ovary, usually with its seeds still inside and sometimes with other flower parts attached. The wall of that mature ovary is called the pericarp.
That definition reaches further than the produce aisle. A tomato, a cucumber and a bean pod are all fruits. The wall can be dry and hard instead of soft and sweet. A strawberry is a fruit too, though part of its flesh comes from tissue below the flower rather than from the ovary alone.
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| A papaya split open. The seeds sit inside the fruit, which grew from the ovary of the flower. That is the angiosperm way. Image: Marek Slusarczyk, CC BY 3.0, via Wikimedia Commons |
Flowers, Cones and How Pollen Travels
Flowers Belong to Angiosperms
Angiosperms have flowers. In a typical flower the sepals protect the bud and the petals often attract visitors. A stamen has a filament topped by an anther, where pollen forms.
The female side is the carpel. It carries a pollen-receiving stigma, a style, and the ovary at the base. A flower can hold one carpel or many, and not every flower has all of these parts.
Gymnosperms have no flowers at all. Their reproductive structures are cones or cone-like shoots: pollen cones that release pollen, and seed cones that hold the ovules.
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| The main parts of a flower, the structure that sets angiosperms apart. Image: Pearson Scott Foresman, public domain, via Wikimedia Commons |
Not Every Gymnosperm Counts on Wind
Wind pollinates most conifers, and it also pollinates grasses, which are angiosperms. Animal pollination is far more common among angiosperms, especially by insects.
Gymnosperms are not limited to wind either. Insects pollinate many cycads and some gnetophytes. A few aquatic angiosperms go further still: Vallisneria pollinates at the water surface, and the seagrass Zostera pollinates underwater.
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| A young female cone of Norway spruce. Ovules form on its scales, with no ovary wrapped around them. Image: Ivar Leidus, CC BY-SA 4.0, via Wikimedia Commons |
Double Fertilization and the Food in a Seed
Two Fusions in One Visit
Angiosperms do something unusual. Two sperm cells take part. One fertilizes the egg and forms the zygote, which becomes the embryo. The other fuses with two polar nuclei in the central cell, and that fusion usually produces endosperm, the food store.
This event is called double fertilization, and the endosperm-forming version is a hallmark of flowering plants.
One qualification keeps the claim honest. Some gnetophytes have a double-fertilization-like event of their own. It is not the same process, and it does not make endosperm. So the angiosperm version is best described as characteristic of the group, not unique to all plants.
Where the Food Sits
Food storage differs between the two groups. A gymnosperm seed is usually packed with haploid tissue from the female gametophyte. An angiosperm seed usually holds endosperm instead, or stores its food in the cotyledons, or in both.
Cotyledon number is one way angiosperms get sorted. Monocots such as grasses and lilies have one cotyledon. Eudicots such as oaks and beans have two.
The older word "dicot" is worth retiring. It lumped together plants that do not share a single ancestor, so it is not a valid modern group. Eudicots is the name for the large branch, and a few early-diverging angiosperms with two cotyledons sit outside it.
Wood, Leaves and Where Each Group Lives
Tracheids, Vessels and Growth
Wood in most gymnosperms carries water through tracheids, long cells that also help support the trunk. Angiosperm wood usually adds vessel elements, wider cells that join into continuous pipes.
Gnetophytes break the pattern again, because they have vessels too. The lumber trade calls conifer timber softwood and flowering-tree timber hardwood. Those labels describe the source group, not how hard the board feels.
Almost all gymnosperms are woody. Angiosperms cover a wider range, from oaks to dandelions. Most monocots do not grow true wood, because they lack the usual cambium, though bamboo manages tough woody stems by other means.
Leaves and Living Places
Conifers often carry needles or small scales, which limit water loss. That is a common habit rather than a gymnosperm rule. Ginkgo has fan-shaped leaves, cycads have large compound leaves, and some gnetophytes have broad leaves.
Angiosperm leaves vary just as widely, from broad tropical blades to the narrow straps of grass. Where the two groups live differs too. Gymnosperms dominate boreal forests and many cold, dry or high mountain sites. Angiosperms dominate most other habitats, including tropical forests and grasslands.
Diversity is lopsided in the same direction. Roughly 1,100 to 1,200 gymnosperm species are alive, against a rough estimate of 330,000 to 350,000 angiosperms. One Kew estimate counted about 369,400 flowering plants among some 390,900 known vascular plants, close to 94 percent. Treat those counts as estimates, since checklists keep changing.
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| A squirrel left these spruce cones stripped, and the seeds lie in the open. No fruit holds them, which is exactly what "naked seed" means. Image: W.carter, CC BY 4.0, via Wikimedia Commons |
| Feature | Gymnosperms | Angiosperms |
| Seed enclosure | Ovules and seeds in the open, on scales or stalks | Ovules inside an ovary, which becomes the fruit |
| Reproductive structure | Cones or cone-like shoots, never flowers | Flowers, often with sepals, petals, stamens and carpels |
| Fertilization | No endosperm-forming double fertilization | Double fertilization forms a zygote and usually endosperm |
| Pollination | Mostly wind in conifers; insects in many cycads | Animals common; wind pollinates grasses and many trees |
| Seed food tissue | Usually haploid female gametophyte tissue | Endosperm, cotyledons, or both |
| Wood | Mostly tracheids; vessels only in gnetophytes | Usually vessel elements as well as tracheids |
| Leaves | Often needles or scales, but also fan and compound | Broad leaves, grass blades and everything between |
| Living species | About 1,100 to 1,200 | Roughly 330,000 to 350,000 |
How the Two Groups Are Related
Angiosperms Are One Branch, Gymnosperms Are Messier
Angiosperms form a single clade, meaning one ancestor and all of its descendants. Living gymnosperms are supported as a group as well, but the arrangement inside it is more tangled than old diagrams suggest.
In a leading current hypothesis the gnetophytes sit among the conifer lineages, which would make the conifers alone an incomplete group. That is a detail for later study, so the safest summary at this level is simple: both groups are seed plants.
When Each Group Appeared
Gymnosperm origins are placed around the mid-Devonian, roughly 385 million years ago, based on current reviews. Angiosperm origins are far less certain.
Molecular work hints at an early history that may reach back toward the Jurassic. Even so, the clearest fossils and the great burst of diversification are Cretaceous. So say that angiosperms diversified greatly through the Cretaceous and rose to dominance over that span, not on one fixed date.
Key Terms in Plain English
| Term | What it means here |
| Angiosperm | A flowering plant; its seeds develop inside a fruit. |
| Gymnosperm | A seed plant whose seeds are not enclosed in a fruit. |
| Ovary | The flower part that holds the ovules and becomes the fruit. |
| Ovule | The structure that becomes a seed after fertilization. |
| Fruit | A mature ovary, usually with its seeds and sometimes other tissue. |
| Pericarp | The wall of a mature ovary, which is the fruit wall. |
| Carpel | The female flower part: stigma, style and ovary. |
| Stamen | The male flower part: filament plus anther. |
| Anther | The part of the stamen where pollen forms. |
| Stigma | The surface that receives pollen grains. |
| Style | The stalk that connects stigma to ovary. |
| Double fertilization | Two fusions in angiosperms: egg and polar nuclei. |
| Endosperm | The food tissue of many angiosperm seeds, usually triploid. |
| Cotyledon | A seed leaf that stores or absorbs food. |
| Monocot | An angiosperm with one cotyledon, such as a grass. |
| Eudicot | An angiosperm with two cotyledons, such as an oak. |
| Vessel element | A wide water-carrying cell typical of angiosperm wood. |
Key Takeaways
- The core difference is the ovary: angiosperm seeds form inside one.
- Gymnosperm seeds sit in the open, often on the scales of a cone.
- A fruit is a mature ovary, so tomatoes and bean pods count as fruit.
- Angiosperms have flowers; gymnosperms have cones and no flowers.
- Double fertilization and endosperm are characteristic of angiosperms.
- Wind and animals both pollinate; gymnosperms are not wind-only.
Frequently Asked Questions
Do gymnosperms have flowers?
No. Gymnosperms make cones or cone-like shoots instead. Flowers belong to angiosperms.
Is a pine cone a fruit?
No. A fruit develops from an ovary, and a cone has no ovary. A cone is a cluster of scales that carry the seeds in the open.
Are gymnosperms all evergreen with needles?
No. Larches are deciduous conifers, Ginkgo loses its fan-shaped leaves each autumn, and cycads carry large compound leaves.
Did angiosperms simply replace gymnosperms?
Not really. Angiosperms became dominant in many habitats, but gymnosperms still form vast boreal forests and do well in cold, dry and high places.
Key references
• OpenStax Biology 2e: Angiosperms
• OpenStax Biology 2e: Gymnosperms
• OpenStax Biology 2e: Reproductive development and structure
• University of Minnesota: Fruit morphology
• Yang et al. (2024): Living gymnosperms review
• Kew: State of the World's Plants (vascular plant counts)
Images: Wikimedia Commons, with the author and license named in each caption. This article is general science education.
