Annona.
Custard apples.
About 166 species plus many hybrids and varieties of which about 8 are grown for domestic or commercial use.
Commonly found in Australia are A. reticulata, A. glabra, A. squamosa A. cherimola and the hybrid Atemoya.
Most are small evergreen or semi-deciduous trees or shrubs up to 8–10 m tall.
The short trunk has a dense crown and long drooping branches.
Young branches are often zig zag and some species have rust coloured hairs.
Twigs of A. squamosa are brown with light brown dots (lenticels).
Leaves are on stalks or petioles from 2 to 22 mm (grooved in A. squamosa).
Leaves in all are simple, entire, and alternately arranged in 2 ranks (distichous).
Some species have reddish hairs on the stalk and/or leaves.
Leaf blades are commonly elliptic to ovate, some lanceolate or oblong.
They are from 15 to 25 cm long and 7 to 10 cm wide.
Tips almost always pointed (acute to acuminate) and bases are rounded or obtuse.
Leaves are pinnately veined and they are prominent on under surface.
Flowers in all may be solitary or in clusters of 2 to 4.
They may appear to be opposite the leaves, axillary or on old wood.
Flowers droop, never fully open and are 2.5 to 3 cm long; Atemoya are up to 6 cm.
The perianth is thick, fleshy and yellow-green with six to eight tepals the outer ones being larger.
There is a nectiferous disc/glands at the base of the ovary.
All have many, usually short, stamens; and many carpels (with a distinct style and stigma) which
may be free or fused to various degrees.
There are one or two ovules per carpel.
Flowers open as pistillate and change to staminate ones later that day or the next.
Fruits are custard apples, from 10 to 20 cm long with a knobbly green, yellowish or brownish surface.
Black or brown seeds are up to 2 cm long with a fleshy coating.
J.F.
