Key for Portulaca L.

1Stems weak, filiform (0.5 mm wide), creeping, rooting at the nodes; leaves opposite; petals yellow
1'Stems stout, often fleshy, erect or spreading, not rooting at the nodes; leaves alternate; petals white,yellow, pink or purple
2Leaves obovate or spathulate, flat; nodes glabrous or with few stipular hairs; petals yellow
2'Leaves linear to linear-oblong, terete or slightly flattened; nodal hair clusters usually conspicuous; petals white, pink or purple
3Flowers often double; petals 1.5-2.5 cm long; seeds grey
3'Flowers simple; petals 3-6 mm long; seeds grey or black
4Leaves 5-16(-27) x 1-4 mm; petals rose-purple; seeds black
4'Leaves 3-6 x 1-1.5 mm; petals white or whitish-rose; seeds grey to black