Polygonum equisetiforme Sm.
A spreading perennial, with long, wiry, decumbent to erect branching stems from 30 to 90 cm long. Leaves narrow-elliptical, 1 to 4 cm long, falling early. Sheaths pale, with irregularly fringed edges, shorter than the internodes. Flowers 2.5 to 3.5 mm long, in lax spikes. Perianth segments 5, greenish or pink, with a broad white to pinkish margin, joined in their lower third. Achenes dark brown to black, 2 to 4 mm long, longer than the perianth.
Local: Very rare in Gibraltar. Only found around the southern entrance to Buenavista Road. The habitat was destroyed in January 2015 for a housing development, and the species lost for Gibraltar. Grows on waste ground, roadsides and field margins.
Global: Found in south-west Europe, Mediterranean region, south west Asia and the Canary Islands.
Flowers from May, June, July, August, September, October to November