Syzygium unipunctatum—Rolypoly Satinash—MYRTACEAE.

Syzygium unipunctatum

Link to Images on Flickr.

Habitat— Grows as an understory tree in well developed rainforest on a variety of sites, 1 to 6 m tall.

Distribution—Endemic to North East Queensland, widespread in the area. Altitudinal range from sea level to 1200 m.


Local occurrences

Brown's Creek Bicentennial Gardens and The North Coast Regional Botanic Gardens Coffs Harbour.

Leaves.— Simple, opposite, entire, oil dots distinct but sparse, stipules absent, intramarginal vein; leaf blade ovate, apex long acuminate, base cuneate, glabrous; oil dots small, visible with a lens, about 1 to 4 oil dots per reticulation. Leaf blades about 6.2 to 11.4 x 2.1 to 4.7 cm. Midrib depressed on the upper surface; stem shortly 4—winged.

Syzygium unipunctatum
Syzygium unipunctatum

Inflorescence.— Terminal and in the upper axils, bracts deciduous, absent at anthesis. Calyx tube (hypanthium) + pedicel about 2.5 to 4.5 mm long, calyx tube (hypanthium) about 1.5 to 3.5 mm diam., calyx lobes triangular to somewhat rounded, about 0.3 to 0.7 mm long. Petals ± orbicular about 1.5 to 2.2 mm diam., oil dots sometimes obscure, about 30 to 80 per petal. Outer staminal filaments about 2.5 to 7 mm long, anthers about 0.2 to 0.3 x 0.2 to 0.3 mm, with two, small, inconspicuous glands, terminal, near the back of the anther. Ovules pendulous from placentas near the apex of each locule, ovules about 2 to 3 per locule. Style about 3 to 6.5 mm long, shorter than the stamens.

Flowering.—Autumn to Winter

Fruit.—Very depressed, almost discoid, attaining about 8 to 12 x 11 to 15 mm, apex excavated, surface longitudinally ribbed or grooved, calyx lobes persistent, but inconspicuous, pericarp forming a very thin skin (about 0.05 mm thick) around the cotyledons, testa absent or indistinguishable from the pericarp. Seed solitary, only slightly smaller than the fruit, pericarp free from the cotyledons but not easily separable because of the matching grooves and ridges in the surface of the cotyledons and the pericarp. Cotyledons glandular, ruminate, with an amorphous, pale (not dark, even though the structure is pale it may be darker than the surrounding tissue in the cotyledons) central structure, with a distinct vascular connection with the base of the fruit. Radicle basal. Cotyledonary stipules present, small and inconspicuous.

Ripe.—February to March

Syzygium unipunctatum