Nettle (Urtica spp.) and pellitory (Parietaria spp.)

General Information

Family: Nettle family (Urticaceae)
Flowering period in Central Europe: Early spring to early autumn
Months: 6–8

Allergy potential
Low allergenicity (Nettle). Moderate allergenicity (Pellitory, main allergen Par j 2).

Due to familial relatedness pollen of hemp, hops, mulberry, and elm can be cross-reactive.

Botanical Information

Worldwide, from arctic to tropical climates (Nettle and Pellitory).

Habit — Annual or perennial herbaceous. Foliage — Some species leaves are covered with stinging hairs. Reproduction — Flowers hermaphroditic and radially symmetrical, flowers spike-like, racemose, branched, or clustered.

Common species in Europe

Common Nettle (Urtica dioica).
Habit — Perennial, herbaceous. Foliage — Heart-shaped, stalked leaves, serrated leaf margin. Habitats — Riparian forests, forest edges, nitrogen indicator. Reproduction — Monoecious. Flowering period in Central Europe — Late May to September.

Pellitory of the Wall (Parietaria officinalis).
Habit — Perennial, herbaceous. Foliage — Leaves elongated-elliptic, leaf margin entire. Reproduction — Mostly dioecious. Distribution — Common in the Mediterranean region, widespread in South Tyrol. Habitats — Ruderal sites (e.g., field margins).