Miconia crenata

Species of flowering plant

Miconia crenata (syn. Clidemia hirta), commonly called soapbush, clidemia or Koster's curse, is a perennial shrub. It is an invasive plant species in many tropical regions of the world, causing serious damage.

Miconia crenata is a densely branching perennial shrub normally growing 0.5–3 m tall, but sometimes growing 5 m tall, depending on habitat.

Native from tropical areas in the Americas (Mexico to Paraguay as well as the Caribbean region). This species grows in dry to wet tropical climates up to 1200 m of elevation.

"Koster's curse" is a commonly used name in places where the plant grows as a noxious weed, such as Hawaii. It was introduced to Fiji in the late 1800s, likely by a coffee planter named William Parr who shared his seeds with others across the region; however the introduction was apparently misattributed by locals to a neighboring sugar planter named Köster. In Hawaii, M. crenata is replacing the endemic species that formerly dominated the forests and threatens them with extinction. Elsewhere, it is regarded as one of the most problematic invasive species in the Comoros Archipelago, on La Réunion, in the Seychelles and on Mauritius.

In order to keep the weed out of an area the primary management objective should be to minimize and prevent disturbance (Smith Undated). it was first employed on Fiji in 1930 (Simmonds, 1933). Controlling feral pig populations (Sus scrofa) has been widely suggested as an effective means to reduce the spread of M. crenata, as ground disturbance by these exotic mammals is strongly linked to the successful establishment of M. crenata, as well as a number of other invasive plants such as Morella faya. Although sheep have been shown to control most weeds in plantations, they will not eat M. crenata (Francis, 2004). According to Mune and Parham (1967), no effective chemical control for M. crenata exists. However, Teoh et al. (1982) report that M. crenata may be killed by applications of triclopyr. Norman and Trujillo (1995) have found that a mycoherbicide containing Colletotrichum gloeosporioides f. sp. clidemiae as the active ingredient was effective against M. crenata. In New South Wales Australia, there is a hotline number for citizens to call and report to the Department of Primary Industries any noticed occurrences of the plant.