Ziziphus quadrilocularis F.Muell.

Mueller, F.J.H. von (1862) Fragmenta Phytographiae Australiae 3: 57. Type: Ad ripas rupestres fluvii Victoriae. F.M.

Young trees clothed in spines or prickles but older trees unarmed.

Leaf blades about 4-8.5 x 2-5 cm, conspicuously 3-veined with the major pair of lateral veins arising at the very base of the leaf blade. Younger leaves quite hairy on the lower surface of the leaf blade. Stipules small and inconspicuous, caducous.

Inflorescence 1-2 cm long, much shorter than the leaves. Calyx lobes about 2 mm long, pubescent on the outer surface, +/- glabrous within, longitudinally ridged on the inner surface. Petals +/- spathulate, about 1.5 mm long, margins involute, enveloping the stamens. Staminal filaments about 1.5 mm long, inserted outside the broad and flat disk, anthers about 0.5 mm long. Ovary immersed in the disk, about 0.6-0.7 mm diam.

Fruits globular or depressed globular, about 22-28 mm diam. Seeds flat, +/- orbicular, about 7-8 mm diam., enclosed in a stone about 15 mm diam. Cotyledons +/- orbicular, about 6 mm diam.

Cotyledons oblong to +/- orbicular, about 16-18 mm long. First pair of leaves with stipular spines, leaf blade ovate, margins toothed. At the tenth leaf stage: leaf blade ovate, apex acute, base obtuse or slightly cordate, margin serrate from the base to the apex, upper surface glabrous or with a few hairs on the midrib near the base; a single gland present on each side of the margin of the leaf blade at the junction with the petiole; stipules spinose. Seed germination time 25 to 26 days.

Endemic to Australia, occurs in WA and NT. Altitudinal range from near sea level to 200 m. Grows in monsoon forest and beach forest.