Herbs , annual or short-lived perennial, 1-4 dm. Stems 10-20-branched, decumbent to ascending. Leaf blades orbiculate to deltate, 0.7-2.7 × 0.5-1.7 cm, base truncate, rounded, or very broadly cuneate, apex smoothly attenuate or occasionally slightly acuminate. Flowers: involucral bracts 1.5-2 mm; tepals ca. 1.5 mm, nearly equal to bracts. Achenes light brown, symmetric, 0.5-0.8 × 0.3-0.6 mm or less, apex obtuse, mucro ±apical; stipe centered, short-cylindric, abruptly flared basally. Flowering winter-spring. Weedy places, around masonry, woodland and shrub borders, shell mounds, sandy beaches, roadsides; Atlantic and Gulf coastal plains; 0-30 m; Del., Fla., Ga., La., Miss., N.C., S.C., Tex.; Mexico; West Indies; South America. Parietaria praetermissa has been misidentified as P . floridana by some authors.
Reports of P. floridana Nutt., another southern sp., with the lvs 3-nerved from the truncate or rounded base, may be based on small plants of P. pensylvanica.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
A prostrate or ascending small plant with reniform or suborbicular to rhombic-ovate leaves 0.5-1 cm wide, native to se. U.S., has been reported as a weed from Wilmington, Del.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.