Psychotria is one of the largest flowering plant genera with 1682 (700 – 1500) species.
Australia has around 11 species with 3 in S. E. Queensland.
Many species produce a psychedelic chemical.
They are mostly shrubs around 3 m high but there are some trees, climbers and rarely herbs.
The leaves are opposite and on petioles.
The blades are commonly elliptic but can be ovate, obovate, oblong or narrowly elliptic.
The lateral veins may be very hard to see.
Leaves and stems may have rust-coloured hairs especially when young.
Adult leaves can be smooth or have hairs underneath or on both surfaces.
There may be domatia (small pits or clumps of hairs) in the vein axils on the lower surface.
The lanceolate or ovate, interpetiolar stipules have colleter glands at the base inside.
Forming a cap over the terminal leaf bud they usually fall off early.
The mostly terminal inflorescences are branched clusters or heads of small, bisexual flowers.
Flowers may be on a stalk or directly attached.
There are variously sized and positioned bracts and bracteoles.
The bases of the 5 (4 – 6) sepals are fused into a short tube with minute teeth.
The bases of the 5 (rarely 4) petals are fused into a short corolla tube.
The slightly shorter lobes flare out or curve backwards slightly.
Most species have hairs inside the throat of the tube.
Some have hairs on the outer surface of the corolla.
Petals are mostly white with some yellow or greenish.
The 5 stamens insert into the corolla tube at various levels.
The filaments can be long or short with the anthers within or above the corolla tube.
In some species there are hairs on the anthers.
The ovary mostly has 2 locules (rarely 3 or 4) with 1 ovule in each.
The style can be long or short but usually extends beyond the corolla tube.
There are 2 (rarely 3 or 4) stigmatic lobes.
There is a small nectiferous disc at the base of the style.
The fruit are white, red, yellowish or black drupes 1 to 2 cm across.
They typically have 1 or 2 hard seeds (pyrenes).