Gomphrena celosioides.
From South America the Gomphrena weed is naturalised in S.E. Queensland.
The annual or short-lived perennial herbs are are commonly around 35 cm high.
Growing from a deep taproot the stems can be erect, prostrate then erect or just prostrate and forming dense mats.
The branching stems, often wider at the nodes are longitudinally ridged.
Young stems have long silky white hairs or dense woolly ones but these are reduced or lost over time.
The opposite leaves are on a petiole around 5 mm long.
The blades are up to 5 cm long and around 1.5 cm wide.
They can be elliptic, oblong or ovate with a blunt to pointed tip with a mucro (short abrupt point).
The base may run down the petiole and the edge is smooth.
There are few to no hairs on the upper blade surface but the edge and lower surface have few to dense white hairs.
The terminal inflorescences are on a peduncle with a pair of involucral bracts under the flower head.
These leafy bracts are just the upper pair of leaves but they are smaller and have no petiole.
The inflorescence is a dense head of flowers that elongates into a spike.
The heads are around 1 cm across and the spikes can be 4 cm long.
Flowers are directly attached to the hairy receptacle (top of the peduncle).
At the base of each flower is a wide papery triangular white bract.
The 3 to 4 mm long bracts have a short point at the tip (mucro).
Each flower has 2 papery white bracteoles 5 to 6 mm long.
Each boat-shaped bracteole folds around and covers one side of the flower.
The thicker midrib (keel) extends past the tip as a short point or mucro.
On either side of the mucro the upper corners are incised or toothed.
Flowers have 5 papery white tepals around 5 mm long in 2 whorls.
The outer 3 have dense matted woolly hairs at the base of the outer surface.
The inner slightly longer two have similar hairs over the whole outer surface except at the tip.
The filaments of the 5 stamens are fused into a tube with 5 teeth on the rim.
The directly attached anthers lie between the bi-lobed teeth.
The superior ovary has one locule with one ovule.
The style and bi-lobed stigma are under 1 mm long.
The utricles are flattened pear-shaped capsules 2 mm long.
The single brown seed, 1.5 m mm long has a wrinkled surface.
A few varieties have been described.
J.F.
