• You are here:
• Simple Key
• All other flowering non-woody plants
• All other herbaceous, flowering dicots
• Urtica dioica

Urtica dioica — stinging nettle

Facts

Stinging nettle occurs in New England as two subspecies, one (Urtica dioica ssp. gracilis) is native, while the other (U. dioica ssp. dioica) is introduced. The native species can be recognized in that male and female flowers appear on a single plant (monoecious), and the plant has only sparse stinging hairs, especially on the stem. The native stinging nettle was considered an important medicinal plant by Native Americans.

Habitat

Anthropogenic (man-made or disturbed habitats), floodplain (river or stream floodplains), forest edges, forests, shores of rivers or lakes

Characteristics

• Clonal plantlets

  Bulbils

  the plant does not appear to have bulbils

  Bulblets replace flowers

  there are no bulblets where the flowers are located

• Flowers

  Anther attachment

  the anther is attached by its base to the filament

  Anther color

  the anthers show no hint of a pink, reddish or purplish tint

  Anther opening

  the anthers have narrow slits or furrows that run lengthwise along the anthers

  Anther spurs

  the anthers do not have spurs on them

  Anther tube length

  0 mm

  Calyx growth after flowering

  the calyx grows to cover or partially cover the fruit

  Calyx symmetry

  there are two or more ways to evenly divide the calyx (the calyx is radially symmetrical)

  Carpels fused

  • NA
  • the carpel is solitary or (if 2 or more) the carpels are not fused to one another

  Cilia on petals

  NA

  Cleistogamous flowers

  there are no cleistogamous flowers on the plan

  Corolla morphology

  NA

  Corolla palate

  NA

  Corona lobe length

  0 mm

  Epicalyx

  the flower does not have an epicalyx

  Epicalyx number of parts

  0

  Filament surface

  • NA
  • the filament is smooth, with no hairs or scales

  Flower description

  the flower has a superior ovary, and lacks a hypanthium

  Flower orientation

  • the flower bends downwards or hangs downwards
  • the flower points upwards or is angled outwards

  Flower petal color

  NA

  Flower reproductive parts

  the flower has either only pollen- or only seed-producing parts

  Flower symmetry

  there are two or more ways to evenly divide the flower (the flower is radially symmetrical)

  Flowers sunken into stem

  no

  Form of style

  NA

  Fringed petal edges

  NA

  Fused stamen clusters

  NA

  Fusion of sepals and petals

  both the petals and sepals are separate and not fused

  Horns in hoods (Asclepias)

  NA

  Hypanthium

  the flower does not have a hypanthium

  Hypanthium length

  0 mm

  Inflorescence length

  30–70 mm

  Inflorescence one-sided

  the flowers are arrayed in a spiral around the inflorescence axis or branches, or occur singly, or in several ranks

  Inner tepals (Rumex)

  NA

  Length of flower stalk

  At least 0 mm

  Marks on petals

  NA

  Nectar spur

  the flower has no nectar spurs

  Number of branches in umbel

  0

  Number of carpels

  1

  Number of pistils

  1

  Number of sepals, petals or tepals

  there are four petals, sepals, or tepals in the flower

  Number of styles

  0

  Ovary position

  the ovary is above the point of petal and/or sepal attachment

  Perianth shape

  • the perianth is cupuliform (cup-shaped)
  • the perianth is rotate (platter-shaped, the corolla flattened, circular, with nearly horizontally spreading lobes)

  Petal and sepal arrangement

  • the flower includes only one cycle of petals or sepals
  • the flower includes two cycles of petal- or sepal-like structures

  Petal and sepal colors

  green to brown

  Petal appearance

  NA

  Petal base

  NA

  Petal folding in bud

  NA

  Petal folds or pleats

  NA

  Petal glandular dots or scales

  NA

  Petal hairs (Viola)

  NA

  Petal hairs on inner/upper surface

  NA

  Petal length

  0 mm

  Petal length relative to sepals

  NA

  Petal nectaries

  NA

  Petal number

  0

  Petal shape

  NA

  Petal tip shape

  NA

  Petal tips (Cuscuta)

  NA

  Petal width

  0 mm

  Raceme attachment (Veronica)

  NA

  Reproductive system

  • all the flowers on each plant have only carpels or only stamens, with only one type being present on each plant (dioecious)
  • each flower has only carpels or only stamens, but both types of flower are present on each plant (monoecious)

  Scales inside corolla

  NA

  Sepal and petal color

  NA

  Sepal appearance

  the sepals are green or brown, and leaf-like in texture

  Sepal appendages

  the sepals do not have appendages on them

  Sepal appendages (Oenothera)

  NA

  Sepal auricles

  the sepals have no auricles

  Sepal cilia

  the sepals do not have cilia

  Sepal color

  • green to brown
  • pink to red
  • white

  Sepal length

  0.8–1.8 mm

  Sepal number

  4

  Sepal orientation

  • the sepals are pressed against the corolla, or jutting stiffly upward
  • the sepals are slightly curved outwards from the corolla

  Sepal relative length

  NA

  Sepal shape

  • the sepal outline is lanceolate (lance-shaped; narrow, gradually tapering from the base to the tip)
  • the sepal outline is linear (extremely narrow, thread-like)
  • the sepal outline is ovate (widest below the middle and broadly tapering at both ends)
  • the sepal outline is spatulate (roughly spoon-shaped; narrow near the base, suddenly widening to a rounded tip)

  Sepal texture

  the sepals are either very thin but flexible, like a membrane, or they are leaf-like in texture

  Sepal tip shape

  the sepal tip is obtuse (is bluntly pointed)

  Sepal uniformity

  • all the sepals are about the same size
  • one or more of the sepals is much narrower or shorter than the others

  Sepals fused only to sepals

  the sepals are separate from one another

  Spur length

  0 mm

  Spur number

  NA

  Stamen appendages

  stamen appendages are absent

  Stamen attachment

  the stamens are not attached to the petals or tepals

  Stamen lengths differ

  the stamens are all approximately the same length

  Stamen morphology

  • NA
  • the stamens within each cycle are the same

  Stamen number

  4

  Stamen position relative to petals

  the stamens are lined up with the sepals

  Stamen relative length

  anything

  Stamens fused

  the stamens are not attached to one another

  Staminodes

  there are no staminodes on the flower

  Stigma position

  the stigmas are in another position

  Style length

  0 mm

  Style relative length

  NA

  Umbel flower reproductive parts

  NA

  Upper lip of bilabiate corolla

  NA

• Fruits or seeds

  Achene relative orientation

  the achenes are perpendicular to the plane of the perianth (vertical)

  Achene shape

  the achenes are oval in outline

  Achene surface (Polygonum)

  NA

  Achene type

  the fruit is an achene (dry, indehiscent, and usually one-seeded)

  Berry color

  NA

  Capsule color (Viola)

  NA

  Capsule ribs

  NA

  Capsule splitting

  NA

  Fruit (pyxis) dehiscence

  NA

  Fruit cross-section

  the fruit is at least somewhat flattened

  Fruit features (Brassicaceae)

  NA

  Fruit length

  1–1.4 mm

  Fruit length relative to sepals

  the fruit is shorter than its associated sepals

  Fruit locules

  one

  Fruit shape

  the fruit is ovoid (egg-shaped)

  Fruit stalk orientation

  • the fruits curve or droop downwards
  • the fruits point upward or spread or curve outward

  Fruit type (general)

  the fruit is dry but does not split open when ripe

  Fruit type (specific)

  the fruit is an achene (dry, usually one-seeded, does not separate or split open at maturity)

  Fruit width

  0.7–0.9 mm

  Hair type on fruit

  NA

  Hairs on fruit

  the fruits are not hairy

  Legumes (Fabaceae)

  NA

  Mericarp length

  0 mm

  Mericarp segment shape (Desmodium)

  NA

  Other markings on berry

  NA

  Ovary stipe

  the ovary or fruit does not have a stipe

  Ovary stipe length

  0 mm

  Placenta arrangement

  the plant has basal placentation, where one or a few ovules develop at the base of a simple or compound ovary

  Rows of seeds in fruit (Brassicaceae)

  NA

  Schizocarpic fruit compression

  NA

  Schizocarpic fruit segments

  0

  Seed number

  1

  Seed relative length

  the seed is longer than it is wide

  Seed surface

  the seed is smooth or without clear markings

  Seeds comose

  no hairs

  Septum in fruit (Brassicaceae)

  NA

  Wings on fruit

  the fruit does not have wings on it

  prickles on fruits

  the fruits do not have thorn-like defensive structures

• Glands or sap

  Glands on leaf blade

  the leaf blades do not have glandular dots or scales

  Sap

  the sap is clear and watery

  Sap color

  the sap is clear

• Growth form

  Growth form

  the plant is an herb (it has self-supporting stems)

  Horizontal rooting stem

  • the plant does not have stolons
  • the plant has stolons

  Lifespan

  the plant lives more than two years

  Parasitism

  the plant is not parasitic

  Plant color

  the leaves or young stems of the plant are green

  Plants darken when dry

  no

  Spines on plant

  • the plant has no spines
  • there are spines on the plant

  Underground organs

  the plant has a rhizome (a horizontal underground stem with roots growing from it)

• Leaves

  Bracteole number (Apiaceae)

  0

  Bracts in plantain (Plantago)

  NA

  Final leaf segment length (compound lvs only)

  0 mm

  Final leaf segment length to width ratio (compound lvs only)

  0

  Final leaf segment width (compound lvs only)

  0 mm

  Floral bracts

  the flower has one or more bracts associated with it

  Hairs on leaf stalk

  the petiole has hairs on it

  Hairs on underside of leaf

  the underside of the leaf is fuzzy or hairy

  Hairs on upper side of leaf

  • the upper side of the leaf is fuzzy or hairy
  • the upper side of the leaf is not hairy, or it has very few hairs

  Hooked hairs on underside of leaf

  no

  Inflated hairs on leaf

  the leaf blade does not have inflated hairs on it

  Leaf arrangement

  opposite: there are two leaves per node along the stem

  Leaf blade base

  the leaf has a distinct leaf stalk (petiole)

  Leaf blade base shape

  • the base of the leaf blade is cordate (heart-shaped, has rounded lobes at the base)
  • the base of the leaf blade is rounded

  Leaf blade base symmetry

  the leaf blade base is symmetrical

  Leaf blade bloom

  the underside of the leaf has no noticeable bloom

  Leaf blade edges

  the edge of the leaf blade has teeth

  Leaf blade flatness

  the leaf is flat (planar) at the edges

  Leaf blade hairs

  the leaf blade has simple hairs with no glands, and not tangled or wooly

  Leaf blade length

  60–200 mm

  Leaf blade primary vein pattern

  the secondary veins branch off at intervals from the primary vein

  Leaf blade shape

  • the leaf blade is elliptic (widest near the middle and tapering at both ends)
  • the leaf blade is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
  • the leaf blade is ovate (widest below the middle and broadly tapering at both ends)

  Leaf blade surface colors

  the upper side of the leaf blade is relatively uniform in color

  Leaf blade texture

  the leaf blade is herbaceous (has a leafy texture)

  Leaf blade vein pattern

  the major veins form a net-like pattern due to splitting and rejoining

  Leaf blade veins

  the leaf blade has three or more main veins that start at or near the leaf blade base and run from the base towards the tip (it may or may not have secondary veins)

  Leaf blade width

  20–130 mm

  Leaf duration

  the leaves drop off in winter (or they whither but persist on the plant)

  Leaf form

  the leaves are green, with an expanded blade and a leaf-like texture

  Leaf hair orientation

  the hairs are standing up straight or curved in different directions

  Leaf sheath length

  0 mm

  Leaf shiny

  the upper side of the leaf is dull or slightly shiny

  Leaf spines

  there are no spines on the leaf edges

  Leaf stalk

  the leaves have leaf stalks

  Leaf stalk attachment to leaf

  the petiole attaches at the basal margin of the leaf blade

  Leaf stalk base

  the petiole base is narrow where it attaches to the stem

  Leaf stalk length

  25–40 mm

  Leaf teeth and lobes

  • the leaf blade margin has forward-pointing teeth
  • the leaf blade margin has teeth, which themselves have smaller teeth

  Leaf tip

  • the tip of the leaf blade is acuminate (tapers to a long, thin point)
  • the tip of the leaf blade is acute (sharply pointed)

  Leaf tufts in axils

  there are no clusters of smaller leaves growing out of axils

  Leaf type

  the leaves are simple (i.e., lobed or unlobed but not separated into leaflets)

  Leaf types

  There is a gradual change in appearance of the leaves from the base (or near the base) of the plant to those from further up on the stem, with leaves progressively changing as one moves higher on the stem (often becoming shorter, or less toothed/lobed, and/or with shorter petioles).

  Leaf variation

  the leaves are nearly similar in size, prominence of teeth, and length of stalks throughout the stem

  Leaflet number

  0

  Leaflet petiolules

  NA

  Leaves per node

  there are two leaves per node along the stem

  Pinnately compound leaf type

  NA

  Specific leaf type

  the leaves are simple (i.e., lobed or unlobed but not separated into leaflets)

  Stipels

  NA

  Stipule edges

  the stipule margins do not have teeth

  Stipule features

  NA

  Stipule fused to leaf stalk

  the stipules are not fused to the petioles

  Stipule length

  5–15 mm

  Stipule shape

  • the stipules are lanceolate (lance-shaped; widest below the middle and tapering at both ends)
  • the stipules are linear (very narrow with more or less parallel sides)

  Stipules

  the plant has stipules

  Teeth per side of leaf blade

  15–21

• Place

  Habitat

  • terrestrial
  • wetlands

  New England state

  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont

  Specific habitat

  • edges of forests
  • forests
  • man-made or disturbed habitats
  • river or stream floodplains
  • shores of rivers or lakes

• Scent

  Plant odor

  the plant does not have much of a smell

• Stem, shoot, branch

  Branched tendrils

  NA

  Direction of stem hairs

  • the hairs are pressed flat against the plant, pointing towards the plant's tip
  • the hairs point mostly upwards to outwards

  Flowering stem cross-section

  the flowering stem is roughly square

  Hair between stem nodes

  • the stem has hairs between the nodes
  • the stem has no hairs between the nodes

  Hairs between stem nodes

  • the hairs on the stem are plain, without glands or branches, and not tangled
  • the stem has no hairs between the nodes

  Hooked hairs on stem between nodes

  no

  Leaves on stem

  there is at least one full leaf above the base of the flowering stem

  Plant height

  50–300 cm

  Stem bloom

  there is no powdery or waxy film on the stem

  Stem hair distribution

  the hairs on the stem are distributed more of less uniformly

  Stem nodes swollen

  the stem is not swollen at the nodes

  Stem orientation

  • the stems are upright or angled outwards
  • the stems trail at the base, but may turn upwards at the tips

  Stem roughness between nodes

  the stem does not feel rough

  Stem spacing

  the plant is solitary, or a few plants are growing together

  Stem succulence

  the stems are not succulent

  Tendril origin

  NA

  Tendrils

  the plant does not have tendrils

  Wings on stem

  the stem does not have wings on it

Wetland status

Occurs in wetlands or non-wetlands. (Wetland indicator code: FAC)

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae