Key to Urtica

View taxon page for Urtica

(For a list of species in Urtica, use the above link.)

Jepson Manual glossary definitions can be seen by moving your cursor over words underlined with dots.

1. Annual 1–6(8) dm; 

leaf 

Organ arising from a stem, generally composed of a stalk (petiole) and a flat, expanded, green, photosynthetic area (blade); distinguished from a leaflet by the presence in its axil of a bud, branch, thorn, or flower; sometimes with lateral, basal appendages (stipules); either simple (toothed, lobed, or dissected but not divided into leaflets) or compound (divided into leaflets).

 

blade 

Expanded portion of a leaf, petal, or other structure, generally flat but sometimes rolled, cylindric, wavy, or cupped.

18–40(90) mm; inflorescence generally ± head- or spike-like, often < 

petiole 

Leaf stalk, connecting leaf blade to stem; sometimes more or less indistinct.

, of staminate and pistillate flowers; fruit 

deltate 

More or less equilaterally triangular, with the corners rounded or not.

..... U. urens

1' Perennial herb 5–30 dm; leaf blade 60–200 mm; inflorescence raceme- or panicle-like, generally > petiole, of staminate or pistillate flowers; fruit 

ovate 

Egg-shaped (i.e., widest below the middle) in two dimensions (i.e., in one plane), as a leaf.

..... U. dioica

2. Non-stinging hairs on stem, leaf 0 to ± dense, occasionally > 1 mm, those on abaxial veins 

appressed 

Parallel or nearly parallel to and often in contact with surface of origin; used to describe the disposition of hairs, leaves, pedicels, etc.

; stem green ..... subsp. gracilis

2' Non-stinging hairs on stem, leaf dense, < 1 mm, those on abaxial veins 

erect 

Upright; vertically oriented.

; stem gray-green ..... subsp. holosericea

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