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• Pascopyrum smithii

Pascopyrum smithii — western wheat grass

Facts

Western wheat grass is a common grass of sagebrush grassland and pinyon-juniper woodland in the West, as well as Great Plains grasslands. An occasional visitor to New England, it has been collected in Massachusetts and New Hampshire railroads, roadsides and disturbed sites.

Habitat

Anthropogenic (man-made or disturbed habitats)

Characteristics

• Flowers

  Anther length

  2.5–6 mm

  Anther number

  3

  Awn on glume

  the glume has no awn

  Bristles below spikelets

  no

  Floret lower bract texture

  the lemma is thin and flexible

  Floret number

  2–12

  Floret types within spikelet

  all the florets within a spikelet are similar

  Glume awn length

  0 mm

  Glume keel

  NA

  Glume relative length

  neither glume is quite as long as all of the florets

  Glume shape

  the glume is flat or curved in cross-section

  Glume veins

  • 3
  • 5
  • 7 or more

  Glumes per spikelet

  2

  Inflorescence axis hairs

  the inflorescence axis is rough and feels like sand-paper

  Inflorescence axis orientation

  • the inflorescence axis is arched or curved outward
  • the inflorescence axis is straight

  Inflorescence branch length

  0 cm

  Inflorescence branch roughness

  NA

  Inflorescence branches

  • the flowers are attached to branches rather than to the main axis of the inflorescence
  • there are no branch points between the base of the inflorescence axis and the flowers, or they are not obvious

  Inflorescence branches coming off the lowest stem node

  0

  Inflorescence crowding

  NA

  Inflorescence length

  50–170 mm

  Inflorescence type (general)

  the inflorescence is a spike, or is spike-like, lacking obvious branches

  Inflorescence type (specific)

  the inflorescence is a spike (a long unbranched stem with flowers along it that lack stalks)

  Inforescence position

  the spikelets are mainly carried at the end of the stem

  Lemma awn base

  the awn is attached right at the tip of the lemma

  Lemma awn coiled

  • NA
  • the lemma awn is straight or twisted, but not coiled one half turn

  Lemma awn length

  0.5–5 mm

  Lemma awn number

  • the lemma has no awn
  • the lemma has one awn on it

  Lemma awn orientation

  the awn of the lemma is straight

  Lemma cross-section

  the lemma is flat or rounded if you cut across the midpoint

  Lemma hairs

  • the lemma has fine hairs between the veins
  • the lemma is hairless between the veins

  Lemma keel hairs

  NA

  Lemma marginal vein hairs

  • the marginal vein of the lemma has fine hairs on it
  • the marginal vein of the lemma is hairless

  Lemma surface

  the surface of the lemma is relatively smooth (not counting any longitudinal veins or hairs)

  Lemma tip

  the lemma tip is a simple point, with or without an awn (long narrow extension ending in a point)

  Lemma tip shape

  • the lemma tip tapers to a long narrow point (it may or may not also have an awn or teeth at the tip)
  • the lemma tip tapers to a narrow point (it may or may not also have an awn or teeth at the tip)

  Lemma vein number

  • 5
  • 7 or more

  Lemma vein orientation

  the veins on the lemma stay roughly parallel throughout

  Lower glume length

  5–15 mm

  Lower glume relative length

  • the lower glume is nearly as long, or as long as, the upper glume
  • the lower glume is one third to three quarters as long as the upper glume

  One or more florets

  there is more than one floret per spikelet

  Palea relative length

  palea is one half to fully as long as lemma

  Reproductive system

  all the flowers on the plant have both carpels and stamens (synoecious)

  Spikelet axis tip

  there is no extension of the spikelet axis beyond the tip of the spikelet

  Spikelet disintegration

  the spikelet breaks off above the glumes, so that after the florets fall off, the glumes remain

  Spikelet length

  12–30 mm

  Spikelet number per node

  Up to 2

  Spikelet pedicel

  the spikelets do not have pedicels

  Spikelet pedicel length

  0 mm

  Spikelet position

  NA

  Spikelet shape

  • the spikelets are elliptic (widest in the middle, tapering to the ends) in profile
  • the spikelets are oblong (rectangular, but with rounded ends) in profile

  Spikelets per panicle branch

  0

  Spikelets spiny

  the spikelets do not appear spiny

  Tip of glume

  the tip of the glume is not divided (though it may have an awn on it)

  Upper glume length

  5–15 mm

  Upper glume relative length

  the upper glume is more than one half as long as the lowest lemma

  Upper glume shape

  the upper glume is widest at or below the middle

• Fruits or seeds

  Groove on seed

  the caryopsis has a groove running most of its length

  Seed length

  4–5 mm

• Growth form

  Lifespan

  the plant lives more than two years

  Rhizomes

  yes

  Roots

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

• Leaves

  Basal leaves

  the plant has large or prominent tufts of leaves at the base of the flowering stem

  Leaf auricles

  the leaves have auricles

  Leaf blade cross-section

  • the leaf blade is clearly folded or rolled inwards
  • the leaf blade is more or less flat in cross-section, or slightly folded or rolled inwards

  Leaf blade hairs

  • the leaf blade is hairless, but it may have tiny prickles that give it a sand-papery feel
  • the leaf blade is hairy

  Leaf blade length

  2–26 cm

  Leaf blade texture

  • the leaf blade is rough and sandpapery
  • the leaf blade is smooth, or it may have soft hairs

  Leaf blade width

  1–4.5 mm

  Leaf ligule type

  the leaf ligule is in the form of a membrane

  Leaf margin glands

  there are no glands along the edges of the leaf blade

  Leaf sheath closed around stem

  the margins of the leaf sheath are overlapping and not fused together except in the basal half (or less)

  Leaf sheath hair type

  • there are hairs on the surface of the leaf sheath, but the hairs do not have blisters at their bases
  • there are no hairs on the surface of the leaf sheath

  Leaf sheath hairs

  • there are hairs on the surface of the leaf sheath
  • there are no hairs on the surface of the leaf sheath

  Orientation of topmost leaf

  the flag leaf is held upright, or at less than a 45 degree angle out from the stem

• Place

  Habitat

  terrestrial

  New England state

  Maine

  Specific habitat

  man-made or disturbed habitats

• Stem, shoot, branch

  Hairs at nodes

  the stem nodes are hairless or they have very sparse hairs

  Plant height

  20–100 cm

  Stem hairs

  the stem is nearly to completely hairless

  Stem orientation

  the stems are upright

  Stem spacing

  • the stems grow close together in compact clusters or tufts
  • the stems grow singly or a few together (they may form diffuse colonies)

Wetland status

Usually occurs in non-wetlands, but occasionally in wetlands. (Wetland indicator code: FACU)

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae