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• Amphicarpum amphicarpon

Amphicarpum amphicarpon — Pursh's blue maidencane

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

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)

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae