[2] Species in the section are found primarily in Western and Central Europe, Central Russia, the Caucasus, and Morocco.

[3] The section contains a variety of types of plants including shrubs, shrublets, and wiry or soft herbs that grow to be up to 2.5 metres (8.2 ft) tall.

They will either be glabrous or have simple hairs and have dark black glands on their leaves.

[4] Section Adenosepalum contains thirty species divided into four subsections as well as two nothospecies.

In addition, H. annulatum has three recognized subspecies and H. aethiopicum has two.