Herbs, perennial from crown, 1-8dm. Stems ascending, erect, or decumbent. Leaf-blades narrowly to broadly elliptic, lance-elliptic, or ovate, 1.3-9 × 0.8-4.5 cm, base attenuate, cuneate, or broadly rounded, apex abruptly acuminate to long-attenuate. Flowers: involucral-bracts 1.5-2.5 mm; tepals ca. 2-3.5 mm, longer than bracts. Achenes dark-brown, symmetric, 1-1.2 × 0.6-0.9 mm, apex acute, mucro absent or minute; stipe centered, on cylindric base.
Phenology: Flowering all year, with peak in late winter–spring.
Habitat: Cracks in sidewalks, ballast heaps, waste places, frequently about ports and coastal areas
Elevation: 0-200 m
Distribution
Introduced; Calif., Fla., La., Mich., N.J., N.Y., Pa., Tex., Eurasia, n Africa
Discussion
Parietaria judaica, which, in North America, is most abundant in scattered localities in California, is the only long-lived perennial species of Parietaria in the flora. Because of confusion in Europe over the correct name, plants in North America have been called P. judaica, P. officinalis of authors, not Linnaeus, P. officinalis var. erecta (Mertens & Koch) Weddell, and P. officinalis var. diffusa (Mertens & Koch) Weddell. For a clarification of the nomenclature and taxonomy of this complex, see C.C. Townsend (1968).
Parietaria judaica was first reported from Louisiana as P. diffusa Mertens & Koch, another name commonly used on herbarium specimens (J.W. Thieret 1969).
Selected References
None.