Red pigweed (munyeroo, purslane)
Portulaca oleracea

Stems - very fleshy or watery, smooth, reddish-green to purplish-red, repeatedly branched and often forming circular mats 30-60cm in diameter or larger.

Cotyledons (seed leaves) of emerging seedlings 2-5mm long, and half or less wide, thick, fleshy and reddish or reddish-green on a bright red stalk; leaves mostly alternate (1 per node) except the first few apparently opposite (2 per node), and those near the tips of branches crowded together; all leaves flat but thick and fleshy, deep green to reddish-green, broadest near the rounded or squared tip and narrowed towards the base, completely hairless.