Brief Summary from
the Encyclopedia of Life
by Jacqueline Courteau
Pond Apple
Annona glabra
Annona glabra, known
as pond-apple, alligator-apple, swamp-apple, corkwood, and
monkey-apple, is a tropical fruit tree in the family Annonaceae.
Related species include cherimoya (A. cherimola) and soursop (A. muricata).
It
is native to southern Florida in the United States (including the
Everglades), the Caribbean, Mexico, Central and South America, West
Africa, and South Asia (Sri Lanka); it is an aggressive invader in the
Pacific region. A. glabra grows in swamps and tolerates saltwater; it cannot grow in dry soil.
The
trees reach a height of 15 m. They have thin, gray trunks, often
buttressed at the base. Leaves, which are late deciduous, are ovate to
oblong with an acute tip, 8–15 cm long and 4–6 cm wide. Flowers are
solitary, 2–3 cm across, white to light yellow, with a rose-colored
patch at each sepal base. Fruits are oblong to spherical, 7–15 cm long
and up to 9 cm diameter (Wikipedia 2011). Fruits disperse by floating
on water.
A. glabra
appears to have naturally colonized West Africa from seeds transported
on water from tropical America (Csurshes and Edwards 1998, ISSG 2011).
Pond-apple fruits are eaten by many animal species: the common name
alligator-apple is said to come from the fact that American alligators
eat the fruit. The fruit has pungent to aromatic flesh, which is edible
for humans, and can be made into jam. Some people consider the flavor
agreeable, while others have characterized it as “insipid” or “scarcely
desirable” (FNA 2011, FOC 2011). The flavor and texture are considered
inferior to the related cherimoya and soursop, and the fruit has never
attained popular use.
However, a recent study (Cochrane et al.
2008) suggests that an extract from pond-apple seeds contains
anticancer compounds that could be used pharmaceutically. A. glabra is used as a hardy rootstock for grafts of more commercially desirable related fruits, such as soursop and sugar-apple (A. squamosa). Other than this, it is not cultivated widely.
Through its introduction as a rootstock, however, A. glabra
has escaped cultivation and become weedy or invasive in Pacific
countries including Fiji, French Polynesia, Vietnam, and Australia
(PIER 2011). The Global Invasive Species Database describes it as “a
highly invasive woody weed that threatens wetland and riparian
ecosystems of wet tropics, world heritage areas and beyond.” (ISSG
2011). It can invade fresh, brackish and saltwater areas and its
thickets are capable of replacing whole ecosystems. Its seed is
primarily dispersed by water, especially during floods. Disturbed
flood-prone ecosystems are most at risk from pond apple invasion,
particularly mangroves, melaleuca woodlands, riparian areas, drainage
lines, coastal dunes and islands (Australian Government 2003). In
estuaries and mangrove swamps, it can outcompete grasses and sedges,
inhibit germination of Melaleuca species, and alter fire regimes (ISSG
2011). It is categorized as a Class 2 weed in Australia, which
indicates that it has spread over substantial areas of Australia
(particularly in Queensland), and has serious impacts that must be
controlled (Queensland 2007). Its sale in Australia for any purpose is
prohibited.
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© Jacqueline Courteau
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