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Sphenopholis pensylvanica — swamp wedgescale

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Facts

Swamp wedgescale, a wetland grass, reaches the northern limit of its range in New England, where it is very rare. It is known from Connecticut, Massachusetts and Rhode Island.

Habitat

Marshes, meadows and fields, shores of rivers or lakes, swamps

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
  • Connecticut
  • Massachusetts
  • Rhode Island
Leaf blade width
1–8 mm
Inflorescence branches
the flowers are attached to branches rather than to the main axis of the inflorescence
Spikelet length
5–9.5 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
0–9 mm
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 ligule length
0.2–1 mm
Anther length
0.5–1.8 mm
Show all characteristics
  • Flowers

    Anther length
    0.5–1.8 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
    2–3
    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
    neither glume is quite as long as all of the florets
    Glume shape
    the glume is V-shaped in cross-section
    Glume veins
    • 1
    • 3
    • 5
    Glumes per spikelet
    2
    Inflorescence arrangement
    the spikelets are uniform
    Inflorescence axis orientation
    • the inflorescence axis bends downwards or hangs
    • the inflorescence axis is arched or curved outward
    • the inflorescence axis is straight
    Inflorescence branch roughness
    • the inflorescence branches are smooth or only slightly rough
    • the inflorescence branches are somewhat to very rough
    Inflorescence branches
    the flowers are attached to branches rather than to the main axis of the inflorescence
    Inflorescence crowding
    the panicle is somewhat to very spread out, with clearly-evident branches
    Inflorescence length
    70–350 mm
    Inflorescence length to width ratio
    3.5
    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
    Inflorescence width
    20–100 mm
    Inforescence position
    the spikelets are mainly carried at the end of the stem
    Lemma awn base
    the awn is attached at the upper half of the lemma
    Lemma awn coiled
    • NA
    • the lemma awn is straight or twisted, but not coiled one half turn
    Lemma awn length
    0–9 mm
    Lemma awn number
    • the lemma has no awn
    • the lemma has one awn on it
    Lemma awn orientation
    the awn of the lemma on dried or older plants is curved or bent outwards
    Lemma base hair length
    0 mm
    Lemma base hairs
    the lemma is hairless or feels just a tiny bit rough at the base
    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
    • the keel of the lemma is rough, or has fine hairs
    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 split into two or more points
    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
    3.5–5.5 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 more than one floret per spikelet
    Palea length
    2–3.5 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 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
    • the spikelet breaks off below the glumes
    Spikelet length
    5–9.5 mm
    Spikelet number per node
    Up to 0
    Spikelet pedicel
    the spikelets have pedicels
    Spikelet shape
    the spikelets are obovate (egg-shaped but with the widest point above the middle) in profile
    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
    3.6–6.2 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 above the middle
  • Growth form

    Horizontal rooting stem
    no
    Lifespan
    the plant lives more than two years
    Rhizomes
    no
    Roots
    there are only slender roots on the plant
  • Leaves

    Leaf auricles
    the leaves do not have auricles
    Leaf basal lobe hairy
    NA
    Leaf blade cross-section
    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
    4–20 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
    1–8 mm
    Leaf ligule length
    0.2–1 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 color and persistence
    the leaf sheathes are off-white to light-brown and mostly persist in older leaves
    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 outward at more than a 45 degree angle from the stem, or it curves downwards from the horizontal
    • the flag leaf is held upright, or at less than a 45 degree angle out from the stem
  • Place

    Habitat
    wetlands
    New England state
    • Connecticut
    • Massachusetts
    • Rhode Island
    Specific habitat
    • marshes
    • meadows or fields
    • shores of rivers or lakes
    • swamps
  • Stem, shoot, branch

    Hairs at nodes
    the stem nodes are hairless or they have very sparse hairs
    Plant height
    30–120 cm
    Roots at lower stem nodes
    no
    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

Wetland status

Occurs only in wetlands. (Wetland indicator code: OBL)

In New England

Distribution

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

Conservation status

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

Connecticut
unrankable (S-rank: SU)
Massachusetts
extremely rare to rare (S-rank: S1S2), threatened (code: T)
Rhode Island
extremely rare (S-rank: S1), state threatened (code: ST)

From Flora Novae Angliae dichotomous key

4.  Sphenopholis pensylvanica (L.) A.S. Hitchc. NC

swamp wedgescale. Eatonia pensylvanica Gray; Trisetum pensylvanicum (L.) Beauv. ex 
 Roemer & J.A. Schultes • CT, MA, RI. Open swamps, graminoid marshes, wet meadows, mossy seeps and banks along streams.

Native to North America?

Yes

Sometimes confused with

Trisetum flavescens

Family

Poaceae

Genus

Sphenopholis