Smooth: no obvious surface ornamentation, smooth to touch.

Papillate: the surface is covered with tiny roughened structures, sometimes nipple shaped.

Warty: the surface has irregular lumps resembling warts (verrucose).

Ridged/channelled: the surface has obvious grooves or channels, usually running longitudinally (sulcate).

Hairy: the surface is covered with hairs.

Glandular: the surface is adorned with tiny rounded glands which can be on short stalks or stalkless (sessile). These glands are often a different colour to the sepal.