The sepals are sometimes free or separate from each other, at other times they are united to a greater or less extent; in the former case, the calyx is polysepalous, in the latter gamosepalous or monosepalous.
The venation is useful as pointing out the number of leaves which constitute a gamosepalous calyx.
In a gamosepalous calyx the sepals are united in various ways, sometimes very slightly, and their number is marked by the divisions at the apex.
- Gamosepalous five-toothed calyx of Campion (Lychnis).
S, Sepals joined to form a gamosepalous calyx; c, corolla consisting of tube and spreading limb; a, stamens springing from the mouth of the tube; p, pistil.