Rhysotoechia robertsonii (F.Muell.) Radlk.

Sapindaceae

Radlkofer, L.A.T. (1879) Sitzungsberichte der Mathematisch-Physikalischen Classe der k. b. Akademie der Wissenschaften zu Munchen 4 : 522.

Robert's Tuckeroo

Lenticels often sparsely distributed. A cream layer is often visible beneath the subrhytidome layer before the first section of the outer blaze.

Leaflets about 6-10 in the compound leaf, each leaflet blade about 7-17 x 2.5-5.5 cm. Midrib and main lateral veins slightly raised on the upper surface. Leaflet stalk swollen at its junction with the compound leaf rhachis. Compound leaf rhachis flattened or with a slight ridge on the upper surface.

Panicles about 14-25 cm long, pedicels about 2-4 mm long. Calyx lobes about 2-3 mm long. Petals about 2 mm long, with thickened basal margins, puberulent inside. Stamens usually eight, filaments about 1-2 mm long, clothed in white hairs. Disk bright yellow-green, stamens inserted inside the disk.

Fruit shortly stipitate, obovoid or subglobose, about 16-28 x 22-32 mm, 3-locular, orange-yellow, with a red flush. Valves reticulate when dry, glandular on the inner surface. Aril small, yellowish, basal and lateral. At maturity, seeds surrounded by a sloppy translucent fluid which can be mistaken for an aril. Cotyledons green.

First pair of true leaves ovate, midrib raised on the upper surface. At the tenth leaf stage: leaf or leaflet blades elliptic to obovate, apex acuminate, base attenuate, glabrous on the upper surface; leaflet stalks short on compound leaves, hairy; petiole and rhachis of compound leaf often winged. Seed germination time 11 to 53 days.

Endemic to NEQ, restricted to the area between Rossville and Tully. Altitudinal range from sea level to 800 m. Grows as an understory tree in well developed rain forest on a variety of sites.

A tree with attractive form that can be very colourful when in fruit and deserves to be introduced to horticulture.

Cupania robertsonii F.Muell., Fragmenta Phytographiae Australiae 5: 146(1865), Type: In silvis ad sinum Rockinghams Bay. Dallachy. Rhysotoechia contermina Domin, Bibliotheca Botanica 89(4): 905(1928), Type: Nordost-Queensland: Regenwalder bei Harvey Creek (DOMIN XII. 1909).