US Army Corps of Engineers
Alaska District

Identification Keys

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  • Wetland Identification Keys

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Identification Keys

These are a few keys designed to be used in the field.  The keys were made to help distinguish selected Carex or sedge species, Salix or willow species, and Viola or violet species.

Carex - Sedge Key

Carex species:

The inflorescence is composed of tiny flowers that lack petals, they look like tiny seeds and are called perigynia, protruding out of the top of the perigynia are the stigmas (which are easily seen early in the season), the number of stigmas vary and can be helpful and important in identification.

C aquatilis (OBL)

lowest bracts: equals or exceeds inflorescence
Terminal spike: upright, staminate

Lateral spike: pistillate, sessile

Stigmas: 2

Perigynia Color: pale brown, greenish-yellow

Other: grow singly or tufted

C limosa (OBL)

lowest bracts: may not pass inflorescence

Terminal spike: upright, staminate

Lateral spike: peduncled, pistillate

Stigmas:3

Perigynia Color: green to straw colored

Other: reddish to yellowish-brown spikes

C livida (OBL)

lowest bracts: equals or exceeds inflorescence

Terminal spike: upright, staminate

Lateral spike: sessile or slightly removed, pistillate

Stigmas: 3

Perigynia Color:pale glaucous-green

Other: spikes are yellow green

C lyngbei (OBL)

lowest bracts: usually extends past inflorescence

Terminal spike: drooping, 2-3 staminate

Lateral spike: dropping, especially lower spikes, pistillate or may be staminate at the top

Stigmas: 2

Perigynia Color: yellow-brown to brown

Other: spikes on long peduncles, perigynia are yellow-brown to brown

C mertensii (FACW)

lowest bracts: almost always exceeds inflorescence

Terminal spike: drooping, pistillate above staminate, sometimes all staminate

Lateral spike: pistillate or with a few staminate at the base

Stigmas: 3

Perigynia Color: light green to pale yellow, becoming reddish at the ends

Other: spikes are club shaped, crowded and drooping

C podocarpa (FAC)

lowest bracts: shorter than or exceeding inflorescence

Terminal spike: 1-2, upright, staminate

Lateral spike: 1-3, pendant on peduncles, pistillate

Stigmas: 3

Perigynia Color: brown, to purplish- brown

Other: spikes are spreading or pendent

C rotundata (OBL)

lowest bracts: leaf like, may exceed inflorescence

Terminal spike: long, staminate

Lateral spike: 2, pistillate, no or short peduncle, upright

Stigmas: 3

Perigynia Color: shiny chestnut brown to straw colored, purplish black when mature

Other: inflorescence is upright

C utriculata = C rhyncophysa (OBL)

lowest bracts: exceeding inflorescence

Terminal spike: 2-4 staminate

Lateral spike: 2-5 upright, pistillate

Stigmas: 3

Perigynia Color: yellowish-green becoming straw colored or reddish purple

Other: 2 short teeth at beack apex

** C rostrata

always found in flooded areas with standing water, blades are glaucous green and u-shaped.

Salix - Willow Key

Willow Species:

Salix alaxensis: Felt-leaf Willow (FAC)

  •  Underside of leaves densely felty and white
  •  Long female catkins attached directly to stem

Salix arbusculoides: Little-tree Willow (FACW)

  • Leaves three to six times long as broad with toothed edges
  • Leaves green above and silky hairs (white or reddish) beneath

Salix arctica: Arctic Willow (NI)

  • Small shrub, may grow prostrate to ground
  • Leaves are oval, hairless above and have long white hairs beneath that form a beard at the tip

Salix barclayi: Barclay’s Willow (FAC)

  • Leaves are hairless and green on top, and whitish underneath
  • Leaves are oval, pointed, and toothed

Salix bebbiana: Bebb’s Willow (FAC)

  • Many branched from the base
  • Leaves are green above with impressed veins and below are whitish with long wavy white hairs, oval shaped
  • Minute stipules (appendage where leaf is connected to branch)

Salix fuscesens: Alaska Bog Willow (FACW)

  • Mostly hidden in grass
  • Leaves hairless, and broadest towards the tips (obovate, pointed)
  • Leaves green on top and white underneath

Salix planifolia – Salix pulchra: Diamond-leaf Willow (FACW)

  • Stems are glossy
  • Leaves are diamond shaped, green above and white below
  • Leaves are not toothed

Salix reticulata: Net-vein Willow (FAC)

  • Leaves are roundish, dark green on top and pale underneath
  • The leaves are deeply veined, like a “net”
  • The petioles or stems of the leaves are long
  • Small shrub (1-15 centimeters)

Salix richardsonii: Richardson ’s Willow (FAC)

  • Stipules are large and persistent
  • Leaves are shiny green above and paler underneath, oval and pointed
  • Catkins grow directly from the stem

Salix scouleriana: Scouler’s Willow (FAC)

  • Gray, smooth bark
  • White or reddish hair on underside of mature leaves, young leaves covered in white hair
  • Leaves are long and linear, broader in the middle and pointed.

Salix sitchensis: Sitka Willow (NI)

Leaves are broader at the tip, but still narrow and pointed, and the margins are not toothed

Leaves green on top and pale underneath

Underneath side of leaves covered in course stiff hairs, giving silky shine

Viola - Violet Keys

Violet Species:

Viola adunca (FAC)

- Slender rootstock

- Leaves are cordate (heart shaped), ovate, obtuse (oval with a point), pubescent (hair present), can be brown dotted, short stemmed

- Numerous short stemmed flowers

- Petals are violet or bluish, often whitish at base


Viola Langsdorffii (FACW)

- thick rootstock

- plant lacking stem in spring

- leaves broadly ovate (oval with a point) to reniform (kidney shaped), somewhat pubescent

- petals are bluish-violet


Viola renifolia (FAC)

- rootstock comparatively thick

- lacking stolons (runners)

- leaves are cordate (heart shaped) orbicular to reniform (kidney shaped), glabrous on both sides, may be pubescent along veins underneath

- petals are white with purple stripes


Viola epipesela ssp. repens (not in green book)

- runners, long and thin rootstock, horizontal

- leaves and stem glabrous (hairless)

- petals are lilac, lower petals have darker veins


Viola Selkirkii (not in green book)

- thin and short rootstock

- leaves are pubescent (hair present) above and glabrous (hairless) below

- petals are violet