Your help is appreciated. We depend on donations to help keep this site free and up to date for you. Can you please help us?

Donate

Native Plant Trust: Go Botany Discover thousands of New England plants

Molinia caerulea — purple moorgrass

Copyright: various copyright holders. To reuse an image, please click it to see who you will need to contact.

Facts

Purple moorgrass has been found in all New England states except New Hampshire, in fields, roadsides and open areas. Its species and common names refer to the deep blue-purple color of its inflorescence, anthers, and late-season leaves. Native to temperate zones of Eurasia, it is the only member of its genus in North America.

Habitat

Anthropogenic (man-made or disturbed habitats), meadows and fields

New England distribution

Adapted from BONAP data

Found this plant? Take a photo and post a sighting.

North America distribution

Adapted from BONAP data

enlarge

Characteristics

Habitat
terrestrial
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • Rhode Island
  • Vermont
Leaf blade width
2–10 mm
Inflorescence branches
the flowers are attached to branches rather than to the main axis of the inflorescence
Spikelet length
4–9 mm
Glume relative length
neither glume is quite as long as all of the florets
Awn on glume
the glume has no awn
One or more florets
there is more than one floret per spikelet
Lemma awn length
0 mm
Anther length
1.5–3 mm
Show all characteristics
  • Flowers

    Anther length
    1.5–3 mm
    Anther number
    3
    Awn on glume
    the glume has no awn
    Floret lower bract texture
    the lemma is thin and flexible
    Floret number
    3
    Glume relative length
    neither glume is quite as long as all of the florets
    Glume veins
    • 1
    • 3
    • 5
    Glumes per spikelet
    2
    Inflorescence arrangement
    the spikelets are uniform
    Inflorescence axis orientation
    • the inflorescence axis is arched or curved outward
    • the inflorescence axis is straight
    Inflorescence branches
    the flowers are attached to branches rather than to the main axis of the inflorescence
    Inflorescence length
    50–400 mm
    Inflorescence type (general)
    the spikelets are borne on stalks or on branches
    Inflorescence type (specific)
    the inflorescence is branched, and the branches do NOT both grow from the same side of the plant AND look like spikes
    Inforescence position
    the spikelets are mainly carried at the end of the stem
    Lemma awn base
    NA
    Lemma awn coiled
    NA
    Lemma awn length
    0 mm
    Lemma awn number
    the lemma has no awn
    Lemma awn orientation
    NA
    Lemma base hairs
    • the lemma has hairs at the base
    • the lemma is hairless or feels just a tiny bit rough at the base
    Lemma base length
    0.1–0.3 mm
    Lemma cross-section
    the lemma is flat or rounded if you cut across the midpoint
    Lemma hairs
    the lemma is hairless between the veins
    Lemma keel hairs
    NA
    Lemma marginal vein hairs
    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 broad 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
    • 3
    • 5
    Lower glume length
    1.5–2.5 mm
    Lower glume relative length
    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
    Spikelet axis tip
    there is an 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
    4–9 mm
    Spikelets spiny
    the spikelets do not appear spiny
    Upper glume length
    2–3 mm
  • Growth form

    Lifespan
    the plant lives more than two years
    Rhizomes
    no
  • Leaves

    Leaf auricles
    the leaves do not have auricles
    Leaf blade width
    2–10 mm
    Leaf ligule type
    the leaf ligule is in the form of fine hairs
    Leaf sheath hairs
    • there are hairs on the surface of the leaf sheath
    • there are no hairs on the surface of the leaf sheath
  • Place

    Habitat
    terrestrial
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • Rhode Island
    • Vermont
    Specific habitat
    • man-made or disturbed habitats
    • meadows or fields
  • Stem, shoot, branch

    Plant height
    15–250 cm
    Stem orientation
    the stems are upright
    Stem spacing
    the stems grow close together in compact clusters or tufts

Wetland status

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

In New England

Distribution

Connecticut
present
Maine
present
Massachusetts
present
New Hampshire
absent
Rhode Island
present
Vermont
present

Conservation status

Exact status definitions can vary from state to state. For details, please check with your state.

Massachusetts
not applicable (S-rank: SNA)

From Flora Novae Angliae dichotomous key

1.  Molinia caerulea (L.) Moench E

purple moorgrass. Aira caerulea L. • CT, MA, ME, RI, VT. Fields, roadsides, and other open areas.

Native to North America?

No

Sometimes confused with

Glyceria melicaria:
leaf sheaths closed and fused at the margins, ligule a membrane, and lemmas with 5 or more veins (vs. M. caerulea, with leaf sheaths open and not fused at the margins, ligule a band of hairs, and lemmas with three veins).

Synonyms

  • Aira caerulea L.

Family

Poaceae

Genus

Molinia