E-Flora BC: Electronic Atlas of the Flora of British Columbia

Parietaria pensylvanica Muhl. ex Willd.
Pennsylvania pellitory
Urticaceae (Nettle family)

Introduction to Vascular Plants

© Curtis Bjork  Email the photographer   (Photo ID #16553)

E-Flora BC Static Map
Distribution of Parietaria pensylvanica
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Species Information

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Annual herb from a taproot; stems sprawling to erect, simple or branched, solitary, hairy, 15-60 cm tall/long.
Basal leaves few, reduced, soon deciduous; stem leaves narrowly egg-shaped to elliptic, 1-9 cm long, slender-stalked, entire.
Inflorescence of small axillary clusters from midstem to stem tip; corollas lacking; calyces dark reddish brown, erect, 1.5-2 mm long, 4-lobed, the lobes abruptly pointed; involucral bracts 3-4, 2-4 mm long, subtending the calyces.
Achenes, brownish, smooth, shining, about 1 mm long.

Source: The Illustrated Flora of British Columbia

Habitat / Range

Moist to mesic shaded areas and disturbed sites in the steppe and montane zones; infrequent in SC BC and rare in NE (Liard Hot Springs) and SW (Sumas Mountain) BC; E to PQ and ME, NH, NY, PA, NC, FL, MS, LA, TX, NM, AZ, CA, and MX.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Parietaria pensylvanica

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class




Elevation (metres) 625 625 625
Slope Gradient (%) 75 75 75
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
175 175 175
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
1 1 1
Modal Nutrient Regime
Number of field plots
 species was recorded in:
Modal BEC Zone Class
All BEC Zones (# of stations/zone) species was recorded in: BG(1)


The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is not evaluated, unknown or variable.

Synonyms and Alternate Names

Parietaria obtusa Rydb. ex Small
Parietaria occidentalis Rydb.
Parietaria pensylvanica var. obtusa (Rydb. ex Small) Shinners

Taxonomic and Nomenclatural Links

Additional Photo Sources

Related Databases

General References