All plants make food by photosynthesis, but they differ in how they move water and how they spread. Those two traits sort the plant kingdom into four big groups.
| Group | Tubes (xylem, phloem)? | Seeds? | Spreads by | Examples |
|---|---|---|---|---|
| Mosses | No | No | Spores | Mosses |
| Ferns | Yes | No | Spores | Ferns, horsetails |
| Conifers | Yes | Yes, in cones | Seeds in cones | Pine, spruce, redwood |
| Flowering plants | Yes | Yes, in fruits | Seeds in fruits | Oak, grass, rose, cactus |
Key idea
Mosses have no tubes for water and stay small; ferns have tubes but no seeds; conifers make seeds in cones; flowering plants make seeds inside fruits.
Why it works
Without xylem, water can only soak from cell to cell, a short trip, so mosses stay low and live in damp places. Tubes let ferns grow tall. Seeds carry a young plant with a food supply and a tough coat, so conifers and flowering plants can spread into dry places. Flowers and fruits add helpers: animals that carry pollen and seeds.
Worked examples
Worked example: Which group?
A plant has tubes, makes no seeds, and has brown dots under its leaves. Which group?
- Tubes but no seeds: a fern.
- The brown dots release spores.
Answer: A fern.
Worked example: Shared traits
Which traits do ferns and pine trees share?
- Both have tubes for water and live on land.
- Only pines have seeds; neither has flowers.
Answer: Tubes (and living on land).
Common mistake
Thinking every plant has flowers and seeds. Mosses and ferns spread by spores, and pine trees make seeds in cones without any flowers. Check the table: only one group has flowers.