Ardisia japonica has only recently (2008) been reported to escape from cultivation and establish populations in the wild (Simon, 2009). Ardisia japonica (often called Japanese ardisia in the horticultural trade) can be purchased from nurseries scattered about the United States, and has been cultivated locally (Alachua County, Florida) at a nursery and a botanical garden. The genus Ardisia is well known to Florida natural land managers. Two introduced species have been designated as FLEPPC Category I species (A. elliptica and A. crenata).
The appearance of Ardisia japonica is distinct from other species of Ardisia that occur in the wild in Florida. Ardisia japonica spreads as a cluster of low, slender stems less than one foot tall that have no branches above ground. It has dull, rough-textured leaves and the berries, which are red, occur singly next to the stem, and are usually not abundant. The other three species (A. elliptica, A. crenata, and A. escallonioides) all grow much taller (over waist high in the case of Ardisia crenata and over head high for the other two species) with thicker stems that have branches. They have smooth, leathery, simple leaves, and have clusters of berries held out away from the main stem. The fruit of A. escallonioides and A. elliptica turns black when ripe.
The habitat that has been invaded in all cases is upland southern hardwood forest on fertile soil. The dominant trees are Carya glabra, Liquidambar styraciflua, Quercus michauxii, Quercus laurifolia/hemispherica, Quercus nigra, Ulmus alata, Celtis laevigata, Fraxinus americana, Pinus glabra, Magnolia grandiflora, and Ostrya virginiana. Common ground cover plants include Carex spp., Thelypteris spp., Oplismenus setarius, Rivina humilis, Viola floridana, and Viola walteri. These sites are some of the best examples of this forest type in Florida.
According to various internet sources, Ardisia japonica grows throughout southern states, from South Carolina to Texas. Land managers in this region – as well as those in northern Florida – should be aware of this plant. The two current FLEPPC Category I Ardisia species have become major problems in Florida, and are not easy to control.
Adapted from R. Simons. Ardisia japonica – Established and Spreading in the Wild in Florida. Wildland Weeds (Summer 2009), 12(3):4-5.