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1 Main lateral veins diverging from the midvein above the usually narrowly cuneate leaf base; larger leaves 2-5× as long as wide; achene 0.9-1.2 mm long
..2 Perennial; achenes dark brown, with an acute apex and lacking a mucro; tepals 2.0-3.5 mm long, longer than the involucral bracts (1.5-2.5 mm long); [exotic weed]; [subgenus Parietaria]
..2 Annual; achenes light brown, the apex rounded but with an apical mucro; tepals 1.5-2.0 mm long, shorter than the involucral bracts (1.8-5.0 mm long); [native, sometimes weedy]; [subgenus Freirea].
1 Main lateral veins diverging from the midvein at the usually truncate, rounded, or broadly cuneate leaf base; larger leaves 1-2× as long as wide; achene either 0.6-0.9 or 1.0-1.4 mm long.
....3 Achene 0.6-0.9 mm long, with a flanged stipe, the mucro located symmetrically at the pole of the achene; leaf blades 0.7-2.7 cm long