Urtica dioica var. dioica stinging nettle Urticaceae URDI*; Bx, bg, br, pb, wv (Yost et al. 1991); R; gr;


Credit: Photo by Aldo De Bastiani

Urtica dioica var. dioica.Photo by Aldo De Bastiani.luirig.altervista.org

Urtica dioica var. dioica is a perennial C3 herb (Pooter et al. 1990), to 2 m, colonial from rhizomes, weak, freely branched, densely hairy, armed with stinging hairs. 

Leaves opposite, to 15 cm long, tip pointed, base lobed, veins palmate at base, armed stinging hairs on both sides, margin coarsely toothed, teeth 5-6 mm deep, stipules narrow, about 1 cm long, sexes on different plants (dioecious). 

Flowers green, minute, in sparsely branched axillary clusters, usually rather lax and elongate; inflorescence longer than petioles, flowers wind pollinated. 

Fruit dry. 

Urtica dioica hairs.commons.wikimedia.org

Urtica dioica hairs.commons.wikimedia.org (Accessed 3/2017).

Wetland status: FACU. 

Frequency in NYC: Infrequent. 

Origin: Europe. 

Habitat: Rich, moist soil in open areas or part shade, flood plains. Found in soil pH 7.4. 

Notes: Host to larvae of the mourning cloak butterfly, Nymphalis antiopa, (Nymphalidae); question mark butterfly, Polygonia interrogationis, and the comma butterfly, P. comma (Nymphalidae), (Tallamy 2003; Pyle 1981).