Annual, erect to decumbent, up to 30 cm tall herb. Stem slender, filiform, profusely branched. Leaves with 1-3 cm long, filiform petiole lamina membranous, broadly ovate to suborbicular or rhombic-ovate 1-2 cm long and broad, thinly hairy, truncate or cuneate at the base, obtuse to acute-acuminate at the apex. Cymose flower-clusters sessile, 3-8-flowered, congested, with lower flowers bisexual and upper female. Flowers sessile, bracts linear-lanceolate, c. 2 mm long, equal to or slightly longer than the calyx, acute. Calyx 4-lobed ovate, patent, or connivent c. 1.5 mm long, acute, pilose, slightly or not enlarged in fruit. Achenes ovoid, 1-1.5 mm long, brown, shining.

Type: “Habitat in Lusitania, Hispania”.

Distribution: Japan, Siberia, China, Mongolia, Australia, New Zealand, South Asia, Himalayas westwards to Europe and Russia (Ural, Caucasus).

Parietaria deblis Forst.f. is said to be different from Parietaria lustanica Linn. by having patent sepals and asymmetrical achenes as indicated by Ball. l.c. I have sinked the former taxon in the synonymy of Parietaria lustanica as many specimens show continuous variation in sepals and achene characters.