Myrsine is a near-cosmopolitan genus of flowering plants in the family Primulaceae, with roughly 283 accepted species distributed across the tropics and subtropics. Most members are evergreen shrubs or small trees with leathery, simple, alternate leaves arranged along woody stems. The genus is concentrated in regions such as New Zealand, Hawaiʻi, sub-Saharan Africa, and Southeast Asia, where it forms an ecologically important part of forest understories and montane scrub.
The flowers are small and clustered laterally in the leaf axils. Plants may be monoecious, dioecious, or polygamous, and field observations have shown that even dioecious individuals sometimes produce bisexual flowers. A characteristic noted across the genus is that flowering and fruiting frequently occur after leaf fall on the older wood, so the blossoms and developing fruits often appear "naked" along bare branches. The fruit is a small, globose, thin-fleshed drupe containing a single seed; in many species it takes nearly two years to ripen, turning from green to black or purple at maturity.
Myrsine was erected by Linnaeus in Species Plantarum (1753). Its modern circumscription is considerably broader than Linnaeus's original concept: under treatments by J. J. Pipoly and J. M. Ricketson, several previously distinct genera — most prominently the Pacific and New World Rapanea and Suttonia, and the Caribbean Caballeria — were folded into Myrsine sensu lato, giving the genus fourteen heterotypic synonyms. The family-level position also shifted: with the APG III system (2009), the old family Myrsinaceae was sunk into an expanded Primulaceae, where the genus now sits in subfamily Myrsinoideae within the order Ericales.
Several species are familiar in horticulture and ethnobotany. Myrsine africana (Cape myrtle) is widely planted as an ornamental boxlike shrub and has a long medicinal history. Myrsine australis (red matipo) and M. lessertiana (kōlea lau nui) are conspicuous components of New Zealand and Hawaiian forests respectively, and M. melanophloeos is a common sub-Saharan tree. The genus is loosely known in the United States as "colicwood."
Distribution
Myrsine is one of the most broadly distributed woody plant genera in the tropics. POWO records its native range as the "Tropics & Subtropics" worldwide, spanning Africa, Asia, the Pacific islands, the Americas, and Oceania. Diversity hotspots include New Zealand, Hawaiʻi, sub-Saharan Africa, and Southeast Asia. The genus has been introduced to Great Britain and is recorded as extinct on the island of Socotra. In the United States it is sometimes called "colicwood."
Ecology
Members of Myrsine are evergreen shrubs or small trees, sometimes monoecious and sometimes dioecious, with persistent leathery leaves arranged alternately along the stems. Flowers are small and grouped in lateral axillary clusters; even on dioecious plants, bisexual flowers are not uncommon. A distinctive feature of the genus is that flowers and fruits often develop after leaf fall, appearing on the bare wood. The fruit is a green-to-black or purple globose drupe, thin-fleshed and typically containing a single seed, which often takes around two years to mature. These long-persisting fruits are an important food source for birds in many of the forests where Myrsine grows.
Conservation
The Global Invasive Species Database (ISSG) currently records no species of Myrsine as a documented invasive. Conservation status varies sharply among species: POWO notes that the genus is recorded as extinct on the island of Socotra, while several island endemics — particularly in Hawaiʻi — are of conservation concern at the species level. A consolidated genus-level assessment is not available.
History
Linnaeus described Myrsine in 1753 in Species Plantarum. For most of its history the genus was treated within its own family, Myrsinaceae, but the molecular phylogenetic work underpinning the APG III system (2009) sank Myrsinaceae into an expanded Primulaceae. In parallel, modern revisions by Pipoly and Ricketson collapsed the Pacific Suttonia, the largely Neotropical/African Rapanea, and several smaller segregate genera into Myrsine itself, so today's circumscription is considerably larger than that recognised through most of the twentieth century.
Taxonomy notes
Myrsine L. was established by Linnaeus in Species Plantarum (1753, p. 196) and sits in the family Primulaceae, subfamily Myrsinoideae, in the order Ericales. POWO currently accepts 283 species in the genus, while the GBIF backbone tallies 401 descendant records when synonyms are included. The genus has been substantially recircumscribed: treatments by J. J. Pipoly and J. M. Ricketson absorbed Rapanea, Suttonia, Caballeria, and eleven other genera as heterotypic synonyms, broadening Myrsine well beyond its original Linnaean concept.
