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Ammophila breviligulata — American beach grass

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Facts

American beach grass is a dominant species of sandy ocean and lake beaches and coastal dunes. There are two subspecies in our region, one of which (Ammophila breviligulata ssp. champlainensis) is found only on Lake Champlain, Vermont and is rare. The other is native to coastal dunes and beaches, but has sometimes been planted as a sand stabilizer in inland locations. For instance, in the early 1800's, residents of Truro, MA were required to plant it on their property to bind the sand.

Habitat

Coastal beaches (sea beaches), dunes, 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
  • terrestrial
  • wetlands
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont
Leaf blade width
0.5–8 mm
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
Spikelet length
10–15 mm
Glume relative length
one or both glumes are as long or longer than all of the florets
Awn on glume
the glume has no awn
One or more florets
there is one floret per spikelet
Lemma awn length
0 mm
Leaf sheath hair type
there are no hairs on the surface of the leaf sheath
Leaf ligule length
1–4.6 mm
Anther length
3–7 mm
Show all characteristics

  • Flowers

    Anther length
    3–7 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
    1
    Floret types within spikelet
    all the florets within a spikelet are similar
    Glume awn length
    0 mm
    Glume keel
    the glume keels are rough or hairy
    Glume relative length
    one or both glumes are as long or longer than all of the florets
    Glume shape
    the glume is V-shaped in cross-section
    Glume veins
    • 1
    • 3
    Glumes per spikelet
    2
    Inflorescence arrangement
    the spikelets are uniform
    Inflorescence axis orientation
    the inflorescence axis is straight
    Inflorescence branch roughness
    the inflorescence branches are smooth or only slightly rough
    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 crowding
    the panicle is somewhat to very congested (crowded), and the branches may not be clearly seen without close inspection
    Inflorescence length
    10–400 mm
    Inflorescence length to width ratio
    9–16
    Inflorescence type (general)
    • the inflorescence is a spike, or is spike-like, lacking obvious branches
    • 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
    Inflorescence width
    10–25 mm
    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 hair length
    1–3 mm
    Lemma base hairs
    the lemma has hairs at the base
    Lemma cross-section
    the lemma is V-shaped 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)
    Lemma tip shape
    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
    7–13 mm
    Lower glume relative length
    the lower glume is nearly as long, or as long as, the upper glume
    One or more florets
    there is one floret per spikelet
    Palea length
    8–14 mm
    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 length
    0 mm
    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
    10–15 mm
    Spikelet number per node
    0
    Spikelet pedicel
    the spikelets have pedicels
    Spikelet pedicel length
    0.5–3 mm
    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
    8–15 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
    3–3.6 mm

  • Growth form

    Horizontal rooting stem
    no
    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 basal lobe hairy
    the lobes at the base of the leaf blades are hairless
    Leaf blade cross-section
    the leaf blade is clearly 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
    Leaf blade length
    15–80 cm
    Leaf blade texture
    the leaf blade is rough and sandpapery
    Leaf blade width
    0.5–8 mm
    Leaf ligule length
    1–4.6 mm
    Leaf ligule type
    the leaf ligule is in the form of a membrane with 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 hair type
    there are no hairs on the surface of the leaf sheath
    Leaf sheath hairs
    there are no hairs on the surface of the leaf sheath

  • Place

    Habitat
    • terrestrial
    • wetlands
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    • Vermont
    Specific habitat
    • dunes
    • sea beaches
    • shores of rivers or lakes

  • Stem, shoot, branch

    Hairs at nodes
    the stem nodes are hairless or they have very sparse hairs
    Plant height
    50–130 cm
    Stem hairs
    the stem is nearly to completely hairless
    Stem orientation
    the stems are upright
    Stem spacing
    the stems grow singly or a few together (they may form diffuse colonies)

Wetland status

Occurs only in non-wetlands. (Wetland indicator code: UPL)

In New England

Distribution

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

Conservation status

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

Maine
SNR (code: SNR)
New Hampshire
uncommon (S-rank: S3), W (code: W)

ssp. breviligulata

Massachusetts
fairly widespread (S-rank: S4)
Vermont
not applicable (S-rank: SNA)

ssp. champlainensis

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

Subspecies and varieties

Ammophila breviligulata Fern. ssp. breviligulata is knownfrom CT, MA, ME, NH, RI, VT. A. breviligulata ssp. champlainensis (Seymour) P.J. Walker, C.A. Paris, & Barrington ex Barkworth is known from VT and is of regional conservation concern.

From Flora Novae Angliae dichotomous key

1.  Ammophila breviligulata Fern. N│EC

American beach grass.  1a. Ammophila champlainensis Seymour • CT, MA, ME, NH, RI, VT. 
Coastal dunes and beaches, sandy lake beaches. Ammophila champlainensis has been treated by many past authors as an endemic of Lake Champlain. However, there has 
been tremendous disagreement over how to treat inland vs. coastal populations of Ammophila breviligulata, because inland populations resembling A. champlainensis also occur around the Great Lakes, in the Saint Lawrence River Valley, and at Lac Saint-Jean. 
A recent study by Delisle-Oldham et al. (2008) looked at the A. breviligulata complex throughout eastern North America and recommended treating it as one polymorphic 
species (noting that Lake Champlain populations were the most distinctive group). Their 
study relied on seven important morphological characters, but phenology and DNA sequence data were not analyzed (note that both of these latter data sets show inland populations 
of A. champlainensis are distinct from A. breviligulata of the Atlantic coast). Despite the 
fact that their study shows overlap in all morphological characteristics when populations 
are examined range-wide, the taxa found in New England are known to be genetically different and flower at different times (as further evidenced by common garden experiments). Therefore, A. champlainensis is recognized here, albeit at a lower rank.

1a.  Plants flowering in June through mid-July, restricted to beaches of Lake Champlain, VT; inflorescence (10–) 12–17.3 (–22) cm tall; glumes acute to short-acuminate at apex, the lower one (7–) 9–10.5 (–12) mm long
 … 1a. A. breviligulata ssp. champlainensis (Seymour) P.J. Walker, C.A. Paris, & Barrington ex Barkworth

1b.  Plants flowering in late July through September, restricted to Atlantic coast beaches and dunes (except where introduced); inflorescence (14.3–) 21–36.5 cm tall; glumes acuminate at apex, the lower one (7.5–) 11–13 mm long … 1b. A. breviligulata ssp. breviligulata

Subspecies champlainensis is known from VT and is of regional conservation concern. 
It occurs on sand beaches of lower (i.e., northern) Lake Champlain. Subspecies breviligulata 
 is known from CT, MA, ME, NH, RI, VT. It is native to coastal dunes and beaches but has been introduced as a sand stabilizer to some inland locations (e.g., VT).

Native to North America?

Yes and no (some introduced)

Sometimes confused with

Leymus mollis:
inflorescence a spike and spikelets with 3-6 florets, and lemmas pubescent over the abaxial surface (vs. A. breviligulata, with the inflorescence a highly congested panicle, spikelets with only 1 floret, and lemmas not pubescent over the abaxial surface).

Family

Poaceae

Genus

Ammophila