Reading the leaf rosette
How to read a leaf rosette from its centre, leaf shape, leaf surface and flowering stalk, with simple checks for a field record.
A rosette is a ring of leaves set close to the ground, with the leaves spreading from a single centre. Many high-ground plants use this arrangement because it keeps leaves low, close together and out of the worst of the wind. A rosette is a good place to start when the flowers are not yet open or have finished.
Start at the centre
Look at the middle of the ring first. Note whether it is open or closed, whether it holds new leaves in a tight bud, and whether a flowering stalk rises from it. The centre often shows whether a plant is still growing or has finished for the season.
Leaf shape and edge
- Length compared with width: long and narrow, oval, or nearly round.
- Edge: smooth, toothed, lobed or fringed with fine hairs.
- Tip: pointed, blunt or notched.
Leaf surface
The surface can be shiny, waxy, hairy or felted. Hairs on leaves are often easier to see with a hand lens than with the eye, and a lens is a common aid in field study. A grey or silver sheen usually points to a dense covering of hairs, which reduces how much the leaf loses in strong sun and wind.
| Feature | Example appearance | What it narrows down |
|---|---|---|
| Leaf edge | Fringed with fine hairs | The genus |
| Leaf surface | Silver or grey sheen | Dense hairs on the leaf |
| Centre | Tight bud at the middle | Active growth this season |
| Stalk | Single stem rising from the middle | Link between the rosette and its flowers |
The flowering stalk
Some rosettes send up a stalk that carries flowers. The stalk's height, its leaves and the number of flowers on it are useful checks. A stalk with leaves along its length differs from a bare one, and the two are seldom confused once compared side by side.
Recording the rosette
A record of a rosette is best made from above and from the side, with a note of the leaf count where it can be counted without disturbing the plant. Leave the plant in place. A rosette that is lifted or torn does not recover, and a record made that way holds nothing a photograph could not show.