PlantaeDB Logo
Login Sign-up

Genus Empetrum in Subfamily Ericoideae

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!

Empetrum Tourn. ex L. is a small, circumboreal genus placed in the family Ericaceae (APG IV, 2016). It comprises about three species (WFO, 2024), with Empetrum nigrum L. as type. The plants are prostrate, mat‑forming evergreen dwarf shrubs dominating acidic peatlands, tundra, alpine scree and boreal heathlands in the Northern Hemisphere, and a disjunct Southern‑hemisphere lineage E. rubrum occurs in the Andes and sub‑Antarctic islands (WFO, 2024).

Morphologically the genus has tiny, revolute, ericoid leaves without stipules, solitary axillary unisexual or perfect flowers bearing a four‑lobed tubular corolla, a superior four‑locular syncarpous ovary with axile placentation, and a fleshy drupe with several small seeds (Kron & Chase, 1993). Its mat‑forming habit, small leaves and persistent indumentum set it apart from most other Ericaceae.

Diversity peaks in high‑latitude habitats. Empetrum nigrum is circumboreal, ranging from peat bogs to alpine tundra (up to 3000 m); E. rubrum is confined to the Southern Andes, sub‑Antarctic islands and southern South America; E. hermaphroditum occupies high‑arctic sites in Greenland and North America (WFO, 2024). Endemism is high in this Southern‑hemisphere lineage, reflecting long‑term isolation on fragmented mountain systems.

Pollination is primarily by small insects (Diptera, Hymenoptera) although wind assistance may occur in exposed sites; fruits are dispersed by birds that ingest the drupes and deposit seeds over long distances (Hedberg, 1990). The base chromosome number is x = 13, with diploid (2n = 26) and tetraploid (2n = 52) populations reported (Favarger, 1965). This polyploidy underlies much of the morphological variation observed across the range.

Taxonomically, Empetrum has been retained as a single genus, but species limits remain contentious. Molecular phylogenies have informed the delimitation of E. nigrum and E. hermaphroditum as subspecies by some authors, while E. rubrum is consistently recognized at species rank (Kron & Chase, 1993).

The fruits are locally collected for jam and liqueur, and the species is cultivated as an ornamental groundcover in alpine and rock gardens (WFO, 2024). It is not a timber tree nor a significant weed, though dense mats can impede regeneration in grazing lands.

Climate warming poses the greatest threat to high‑latitude and alpine populations; monitoring of seed set and genetic diversity remains limited, underscoring the need for long‑term studies as Arctic habitats continue to shift northward.

Pick a Species to see its components: