PlantaeDB Logo
Login Sign-up

Genus Periploca in Tribe Periploceae

In botanical taxonomy, a genus (plural genera) is a rank used to group closely related species within a family. In the hierarchy, genus sits below family and above species.

Genera are defined by shared morphological, anatomical, and genetic characteristics (for example, features of flowers, fruits, seeds, or leaves) that indicate a close evolutionary relationship among the species they contain.

Each genus can include one or more species. Examples include Rosa (roses) and Solanum (nightshades, including tomato and eggplant).

Do you wish to read more about plant taxonomy? Click here!

Genus Description

Suggest a correction!

Periploca (Tourn. ex L.) is placed in Apocynaceae subfamily Asclepiadoideae, and the genus is estimated to comprise about 50–70 accepted species globally. Its center of diversity lies in tropical Africa, with secondary centers in the Mediterranean–Near East and Asia. The type species is Periploca graeca, a familiar element of maquis and riverine woodland in the eastern Mediterranean. Twining or scrambling vines with milky latex mark the genus, and paired opposite leaves are typically lanceolate to ovate, usually without persistent stipules. Inflorescences are few- to many‑flowered cymes; flowers are usually small, often yellow‑green to brownish, with a five‑lobed corolla, a prominent five‑part corona formed by free or basally connate scales, and an apocarpous gynoecium. The pollinaria bear translators (caudicles) enabling insect vectors, while the fruit consists of paired follicles containing seeds that bear a long coma facilitating wind‑assisted dispersal. Regions of diversity follow broad biogeographic patterns: many narrow endemics occur in East and southern Africa’s woodlands and forest edges from near sea level to c. 2000 m, a few species extend through the Arabian Peninsula into the Levant, and fewer taxa reach tropical Asia. Intrinsic biology is typical of Asclepiadoideae: specialized pollinator interactions and anemochorous seed dispersal are implied by pollinarium architecture and coma‑bearing follicles; base chromosome numbers reported for several African taxa are x = 11 (Heitz, 1959). Taxonomically the genus is most often treated in a broad sense, with synonymizations of segregates such as Petalostelma and Parquetina accepted in recent floristic treatments (Goyder & Nicholas, 2002), and current global checklists follow this broad circumscription (POWO, 2024; WFO, 2024). Molecular work consistently positions Periploca within Asclepiadoideae, supporting its monophyly and providing the phylogenetic context referenced in broader apocynaceous syntheses (Endress, Bruyns & Rapini, 2014). Human relevance is limited: P. graeca is occasionally cultivated for ornamental fragrance and its distinctive seedheads, but the group is not widely commercialized nor noted for timber; invasive tendencies are negligible. Conservation status varies by taxon; many African species have restricted ranges and face habitat loss, although the genus itself remains secure. Continued fieldwork and phylogenomic resolution will refine regional delimitations and conservation priorities.

Pick a Species to see its components: