Back to Completed Reports List

  

Ripe berry-like fruits on a mature A. elliptica specimen. Photo courtesy UF/IFAS Center for Aquatic and Invasive Plants. Photographer Ann Murray.

Species Name: 
Ardisia elliptica Thunb.

Common Name(s):
Shoebutton Ardisia, Inkberry, Seashore Ardisia, Ati Popa'a, Mameyuelo

Synonymy:
Ardisia ketoensis Hayata
Ardisia polycephala Wall.
Ardisia solanacea Roxb.
Ardisia humilis Vahl.
Bladhia elliptica (Thunb.) Nakai

Species Description:
Shoebutton ardesia, Ardisia elliptica, is a tropical shrub or small tree not native to Florida but now occurring as an invasive species in the southern half of the state. The typical growth form in undamaged plants is a single, smooth stem that gives rise to short, perpendicular branches. Plants may send up additional stems from the rootstock, particularly after damage. Individuals produce strong taproots that produce highly branched lateral roots.

The leaves are alternate, oblong to oval, pointed at the tips, smooth and leathery/rubbery, 8-20 cm long, pink to reddish in young plants and turning dark green with age. Star-shaped flowers, to 13 mm wide with pale violet-colored petals occur in axillary clusters. Fruits are round, berry-like drupes, 6 mm wide that are white when young and turning red and then dark purple to black when ripe, and capable of staining fingers. The flesh of the ripe fruit is juicy when broken and white in color, and each fruit contains a single seed (Langland and Burks 1998, Francis undated, ISSG).

Potentially Misidentified Species:
Two native Florida plants, marlberry (Ardisia escallonioides) and myrsine (Rapanea punctata) are related to Ardisia elliptica and similar in appearance. Langland and Burks (1998) note that A. elliptica can be distinguished from these native plants by its larger growth habit and conspicuous clusters of violet axillary flowers.

A. elliptica may also be confused in Florida with a non-native congener, the coral ardisia A. crenata, whose distribution in the state is broader but still partly overlaps that of A. elliptica. The scalloped leaf margins and persistent bright red fruits of A. crenata aid in distinguishing it from A. elliptica.

II.  HABITAT AND DISTRIBUTION 

Regional Occurrence:
The native distribution of Ardisia elliptica is not entirely certain, and the original range of the species has variously included India, Sri Lanka, China Taiwan, Malaya, Southeast Asia, Indonesia, and the Philippines (Tomlinson 1986, Langland and Burks 1998, Yuen-Po 1999).

The plant is an introduced exotic that now occurs in the East Indies and Okinawa, Japan, and has become naturalized in south Florida, Hawaii, and the Caribbean (Langland and Burks 1998, Francis undated).

IRL Distribution:
Florida Exotic Pest Plant Council collection records indicate that Ardisia elliptica is present in the southern half of the IRL watershed in St. Lucie, Martin, and Palm Beach counties. Wunderlin et al. (1995) also indicate the plant is present in Brevard County, based on vouchered specimens. Brevard is the northernmost county from which the plant has been collected.

III. LIFE HISTORY AND POPULATION BIOLOGY

Age, Size, Lifespan:
Adult trees can reach a height of 6 m and attain a basal trunk diameter of 15 cm. Adult mortality due to old age is rare in Florida and Francis (undated) suggests a likely lifespan of 10-25 years or more.

Abundance:
Shoebutton ardisia is an understory species that forms dense monotypic thickets in moderately wet soil conditions. This invasive plant is now established in south Florida and is abundant in natural areas such as hammocks, marsh islands, cypress and mangrove habitats, and also in disturbed systems such as altered wetlands and fallow fields (Langland and Burks 1998).

Reproduction:
Reproduction in Ardisia elliptica is sexual and the species flowers and fruits sporadically throughout the year in south Florida (Long and Lakela 1971, Langeland and Burks 1998). Individuals attain sexual maturity in 2-4 years. Flowers are insect-pollinated Individual plants possess both male and female flowers and there is a high degree of autogamy or self-fertilization (Pascarella 1997).

Fruit production is moderate, up to 400 fruits on large adults in bright forested sites (ISSG), but year-round production likely increases the overall reproductive capacity of individuals.

Embryology:
Propagules remain viable after gut passage and seed dispersal has been reported as primarily through frugiverous birds (Langeland and Burks 1998, Francis undated), particularly the gray catbird (Dumetella carolinensis) in Florida. However, recent studies examining the spread of Ardisia elliptica in Everglades national Park suggest that long-distance dispersal by raccoons (Procyon lotor), although less frequent than bird dispersal, may be of primary importance in determining invasion rates (Horvitz and Koop 2005, Koop and Horvitz 2006).

Seeds reportedly do not remain viable for more than 6 months (ISSG). Experimental evidence suggests germination rates are high; 75% of seeds planted in commercial potting mix with no pretreatment germinated 42-81 days after sowing. Seedlings may grow up to 1 m in the first year, but 0.25 to 0.5 m/year is a more typical rate for both seedlings and established shrubs (Francis undated).

IV.  PHYSICAL TOLERANCES

Temperature:
This tropical species is restricted largely to the southernmost Florida counties, most likely due to cold intolerance. Published thermal tolerance information is lacking, but prediction models by Braun (2006) suggest Ardisia elliptica will remain restricted to the southern half of peninsular Florida. In contrast, the models suggest the congener A. crenata (also non-native) has potential to spread through Florida and across the Gulf coast into Texas.

Hydrology:
Ardisia elliptica grows well in moderately wet soil conditions including mesic forest and lower portion of wet forest as well as mangroveanand cypress stands and marsh habitats (Adams 1972, Wagner et al. 1990, Langland and Burks 1998). Tolerance for wet soils is a key feature of shoebutton ardisia's invasive capacity.