Identification:
Shoebutton ardisia is already a widespread pest on the island of Maui, but can be prevented from invading Molokai. This fast growing shrub/small tree grows up to 5 m (17 ft) tall. Young trees have light colored smooth bark. Tolerates shade and is often found growing as an understory shrub in moderately wet lowland areas, such as along the Hana Highway on Maui. New growth is often rosey-pink with smooth light colored bark. Leathery, ALTERNATE LEAVES grow to 20 cm (8 long) with entire margins. Small, pale lavendar STAR SHAPED FLOWER hang near the end of the leaf stalk. Ardisia fruits are 6 mm (< 1 in) in diameter. Each fleshy fruit contains one seed and matures from white in color to inky black with white flesh.

Characteristics:
More information about this pest 

Shoebutton ardisia look-alikes:

Hilo holly (Ardisia crenata):
Bushy shrub that usually grows 0.57 -7 1 m (1.5 - 4 ft) in height. Alternate leaves are dark green above, lighter below, with an oblong shape and WAVY (crenate) MARGINS. Star shaped flowers are pink with yellow anthers. Mature FRUIT is RED.

Strawberry guava (Psidium cattleianum ):
Strawberry guava, a widespread wet forest weed on Maui, Lanai, and Molokai has leaves that are similarly shaped to shoebutton ardisia. In contrast, strawberry guava has WHITE FLOWERS, GOLF BALL SIZED dark red or purple FRUIT (or sometimes occasinally yellow,) and smooth bark with light brown, green, and pink camouflage-type coloration pattern.