Plants are grouped into four divisions that reveal a clear evolutionary trend: decreasing dependence on water for reproduction. Explore bryophytes, pteridophytes, gymnosperms, and angiosperms.
Plants (Kingdom Plantae) are grouped into four major divisions. Moving from bryophytes through to angiosperms, there's a clear evolutionary trend: decreasing dependence on water for reproduction, alongside increasing structural complexity.
| Division | Key features | Reproduces via |
|---|---|---|
| Bryophytes | Simple moss plants; no vascular tissue, no true leaves or roots | Spores — needs water for reproduction |
| Pteridophytes | Rhizome and fronds (leaves) bearing sori (spore clusters); has vascular tissue | Spores — still needs water |
| Gymnosperms | True leaves (often needles) and roots; vascular tissue; cones | Seeds — not enclosed in fruit |
| Angiosperms | True leaves and roots; vascular tissue; flowers | Seeds — enclosed in fruit |
Bryophytes lack vascular tissue (xylem and phloem), which limits their size and ties them to damp habitats. Pteridophytes, gymnosperms, and angiosperms all have vascular tissue, allowing water and nutrient transport over longer distances — enabling larger plants that can grow further from water sources.
Gymnosperms and angiosperms produce seeds rather than spores. A seed contains a protected embryo with a food store, giving it a major survival advantage over a spore. The key difference between the two seed-producing groups is that angiosperm seeds are enclosed in a fruit, while gymnosperm seeds (e.g. in a pine cone) are not.
Give a plant new features one at a time and move it to drier habitats. Where can it still grow and reproduce?
Click each division to compare structure, reproduction, and dependence on water.
| Division | Water dependence for reproduction (%) |
|---|---|
| Bryophytes | 95 |
| Pteridophytes | 70 |
| Gymnosperms | 30 |
| Angiosperms | 10 |