Australian Tropical Rainforest Plants - Online edition

Syzygium aqueum (Burm.f.) Alston


Shrub (woody or herbaceous, 1-6 m tall)
Tree
Click/tap on images to enlarge
Flowers. © B. Gray
Leaves and flowers. © B. Gray
Flowers. © B. Gray
Leaves and fruits. © CSIRO
Fruit, three views and cross section. © W. T. Cooper
Scale bar 10mm. © CSIRO
Cotyledon stage, hypogeal germination. © CSIRO
10th leaf stage. © CSIRO
Family

Alston, A.H.G. (1929) Annals of the Royal Botanical Gardens, Peradeniya 11 : 204.

Common name

Apple, Water; Water Apple; Watery Rose-apple

Stem

A small tree seldom exceeding 30 cm dbh.

Leaves

Oil dots quite numerous. Leaf blades about 8.5-16 x 2.5-6.2 cm. Midrib grooved or depressed on the upper surface. Two intramarginal veins or a double series of loops often visible.

Flowers

Inflorescence peduncles long and slender, about 10-20 x 1 mm, bracts absent at anthesis. Calyx tube (hypanthium) + pedicel about 4-8 mm long, calyx tube (hypanthium) about 3-7 mm diam., calyx lobes dimorphic, broadly triangular to rounded, about 2-4.5 mm long. Petals broadly spathulate, shortly clawed, about 8 x 6 mm, oil dots visible, more than 100 per petal. Staminal filaments glandular, outer filaments about 10-15 mm long, anthers about 0.6 x 0.4 mm, gland terminal, small and inconspicuous. Ovules about 30-40 per locule, placentas central, ovules radiating, ascending. Style about 10-20 mm long, usually exceeding the stamens.

Fruit

Fruits campanulate or broadly campanulate, attaining about 25 x 25 mm, calyx lobes persistent, incurved, about 4-5 mm long, pericarp succulent. Seed usually solitary, sometimes two or more seeds per fruit, sometimes seeds absent, testa adhering somewhat to the slightly rugose surface of the uniformly textured, petiolate cotyledons but almost entirely free from the pericarp at maturity. Radicle lateral.

Seedlings

Cataphylls about 1 or 2 pairs. At the tenth leaf stage: leaf blade elliptic or obovate-elliptic, apex shortly acuminate, base cuneate, glabrous; oil dots small, visible with a lens; two intramarginal veins present; stem 4-winged. Seed germination time 27 to 37 days.

Distribution and Ecology

Occurs in CYP, wild populations are known from the Claudie River area. Altitudinal range probably small, from near sea level to 100 m. Grows as an understory tree in the dry, seasonal rain forest, monsoon forest and gallery forest. Also occurs in India, SE Asia, and Malesia, usually as a cultivated plant.

Natural History & Notes

A small tree with dense dark green leaves but usually grown for the shiny, bright red, pear-shaped fruits.

Plants of exotic origin have been cultivated for many years under the name Water Apple.

This species is of no commercial value as it is unlikely to produce millable logs.

Wood specific gravity unknown. Hyland (1983).

Synonyms
Jambosa aquea (Burm. f.) DC., Prodr. 3: 288(1828). Eugenia aquea Burm. f., Fl. Ind. 1768: 114(), Type: Jambosa aquea Rumphius, Herb. Amboin. 1: 126. t 38, f.2. (1741).
RFK Code
797
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