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Amphicarpum amphicarpon — Pursh's blue maidencane

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Facts

Pursh's blue maidencane was discovered in Nantucket, Massachusetts in 1988, 240 miles north of its previously known northernmost occurrence in New Jersey. The single population on a pond shore in Nantucket is vulnerable to changes in hydrology. This grass has two types of flowers, the aerial flowers producing conventional seeds, the underground flowers being self-fertile (chasmogamous), and producing a few larger, underground seeds.

Habitat

Shores of rivers or lakes

New England distribution

Adapted from BONAP data

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North America distribution

Adapted from BONAP data

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Characteristics

Habitat
wetlands
New England state
Massachusetts
Leaf blade width
5–15 mm
Inflorescence branches
the flowers are attached to branches rather than to the main axis of the inflorescence
Spikelet length
4–8 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
  • there is one floret per spikelet
Lemma awn length
0 mm
Show all characteristics
  • Flowers

    Anther number
    3
    Awn on glume
    the glume has no awn
    Bristles below spikelets
    no
    Floret lower bract texture
    the lemma is hard and firm
    Floret number
    1–2
    Floret types within spikelet
    • NA
    • there are at least two distinct forms of florets within one spikelet
    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
    Glumes per spikelet
    1
    Inflorescence arrangement
    the spikelets are uniform
    Inflorescence axis orientation
    the inflorescence axis is straight
    Inflorescence branches
    the flowers are attached to branches rather than to the main axis of the inflorescence
    Inflorescence length
    30–200 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
    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 cross-section
    the lemma is flat or rounded if you cut across the midpoint
    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)
    Lower glume length
    0 mm
    Lower glume relative length
    NA
    One or more florets
    • there is more than one floret per spikelet
    • there is one floret per spikelet
    Palea relative length
    palea is one half to fully as long as lemma
    Spikelet axis tip
    there is no extension of the spikelet axis beyond the tip of the spikelet
    Spikelet length
    4–8 mm
  • Growth form

    Lifespan
    the plant lives only a single year or less
  • Leaves

    Leaf auricles
    the leaves do not have auricles
    Leaf blade width
    5–15 mm
    Leaf ligule type
    the leaf ligule is in the form of fine hairs
    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 hairs
    there are hairs on the surface of the leaf sheath
  • Place

    Habitat
    wetlands
    New England state
    Massachusetts
    Specific habitat
    shores of rivers or lakes
  • Stem, shoot, branch

    Stem spacing
    the stems grow singly or a few together (they may form diffuse colonies)

Wetland status

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

In New England

Distribution

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

Conservation status

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

Massachusetts
extremely rare (S-rank: S1), endangered (code: E)

From Flora Novae Angliae dichotomous key

1.  Amphicarpum amphicarpon (Pursh) Nash NC

Pursh’s blue maidencane. Amphicarpum purshii Kunth • MA; Nantucket Island. Coastal plain pond shores.

Native to North America?

Yes

Synonyms

  • Amphicarpum purshii Kunth

Family

Poaceae

Genus

Amphicarpum