Elaeocarpus grandis is a large tree that may grow to a height of . The trunk is usually straight and cylindrical with pale grey bark marked by vertical lines. Buttress roots are present even on smaller trees, becoming large and elaborate on older trees. The crown is sparse and open, the branches layered, with the leaves clustered towards the ends of the twigs. The leaves are bright green above and paler below, turning bright red before falling; it is common to see red leaves in the canopy at any time of year. The leaves are
simple, i.e. without divisions or lobes, and arranged
alternately on the twigs. They are
oblong to
elliptic and measure up to long and wide, and are regularly and shallowly toothed. They are held on a
petiole up to long and have many small
domatia on the underside. The blue quandong begins to flower around the seventh year, and the
inflorescences are
racemes up to long, produced in the
leaf axils and on the branches below the leaves. They each bear 12–16 fragrant, pale green to white flowers on
pedicels about long. The flowers measure about wide and long, with five petals that have thin lobes at their apices, giving them a fringed appearance. They have between fifty and seventy
stamens. The fruit is an almost spherical blue
drupe, measuring about in diameter. Beneath the skin there is a thin layer of green flesh around the deeply sculptured stone. The stone contains between two and five seeds.
Phenology Flowering and fruiting appears to occur throughout the year. The Australian botanist
Wendy Elizabeth Cooper has stated that flowering of
E. grandis occurs from October to March and fruit appear in any month. The citizen-science website
iNaturalist compiles phenology data from the observations that are uploaded to it, which shows that flowering has been observed in this species in all months except August, September and October, while fruit were observed in every month but with a significant surge of sightings from June to November. ==Taxonomy and naming==