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Poa saltuensis — old-pasture blue grass

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Facts

Weak spear grass inhabits moist to wet forests, swamps, meadows, cliff bases and rock outcrops. It is divided into two subspecies. The more widespread one is Poa saltuensis ssp. saltuensis. The more restricted (P. saltuensis ssp. languida) is found in Connecticut, Massachusetts, Rhode Island and Vermont, and is regionally rare.

Habitat

Cliffs, balds, or ledges, forests, meadows and fields, ridges or ledges, swamps, woodlands

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
1–6 mm
Inflorescence branches
the flowers are attached to branches rather than to the main axis of the inflorescence
Spikelet length
3–5.6 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
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
0.6–4.6 mm
Anther length
0.6–1.5 mm
Show all characteristics
  • Flowers

    Anther length
    0.6–1.5 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
    2–5
    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
    Glumes per spikelet
    2
    Inflorescence arrangement
    the spikelets are uniform
    Inflorescence axis orientation
    the inflorescence axis bends downwards or hangs
    Inflorescence branch roughness
    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 branches coming off the lowest stem node
    1–3
    Inflorescence crowding
    the panicle is somewhat to very spread out, with clearly-evident branches
    Inflorescence length
    40–240 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
    Lemma cross-section
    the lemma is V-shaped if you cut across the midpoint
    Lemma hairs
    the lemma is hairless between the veins
    Lemma keel hairs
    • the keel of the lemma is hairless
    • 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 has wrinkles that are oriented across the lemma
    • 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 long narrow 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
    5
    Lower glume relative length
    • the lower glume is nearly as long, or as long as, the upper glume
    • 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 length
    2.4–4 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
    Spikelet length
    3–5.6 mm
    Spikelet number per node
    Up to 0
    Spikelet pedicel
    the spikelets have pedicels
    Spikelet position
    the spikelets emerge mainly from the upper halves of the inflorescence branches
    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 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
  • 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
    Leaf blade length
    6–15 cm
    Leaf blade width
    1–6 mm
    Leaf ligule length
    0.6–4.6 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 fused together and form a closed tube except (possibly) at the very top
    • 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 reddish-brown and disintegrate or become shredded 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
  • Place

    Habitat
    • terrestrial
    • wetlands
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    • Vermont
    Specific habitat
    • cliffs, balds, or ledges
    • forests
    • meadows or fields
    • ridges or ledges
    • swamps
    • woodlands
  • Stem, shoot, branch

    Hairs at nodes
    the stem nodes are hairless or they have very sparse hairs
    Plant height
    20–95 cm
    Stem hairs
    the stem is nearly to completely hairless
    Stem spacing
    the stems grow close together in compact clusters or tufts
    Stem thickness at base
    0.8–1.5 mm

Wetland status

Not classified

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
unranked (S-rank: SNR)

ssp. languida

Massachusetts
extremely rare (S-rank: S1), endangered (code: E)
Rhode Island
extremely rare (S-rank: S1), concern (uncertain) (code: C*)
Vermont
extremely rare to rare (S-rank: S1S2)

ssp. saltuensis

Massachusetts
fairly widespread (S-rank: S4)
Vermont
uncommon (S-rank: S3)

Subspecies and varieties

Subspecies saltuensis is known from CT, MA, ME, NH, RI, VT. Subspecies languida is known from CT, MA, RI, VT and is of regional conservation concern.

From Flora Novae Angliae dichotomous key

12.  Poa saltuensis Fern. & Wieg. NC

old-pasture blue grass. 12a. Poa saltuensis Fern. & Wieg. var. microlepis Fern.; 12b. Poa debilis Torr. • CT, MA, ME, NH, RI, VT. Dry-mesic to hydric forests, woodlands swamps, meadows, cliff bases, rock outcrops; ssp. languida is usually found on relatively drier and higher pH substrate than ssp. saltuensis, but many exceptions exist.

1a.  Anthers 0.9–1.5 mm long; lemmas acute to acuminate at the apex, the keel and lateral margins of lemma forming an apical angle of 10–47 degrees, pliable at the apex, with a prominent scarious tip 0.25–0.5 mm long; upper ligules mostly 0.6–2 mm long 
… 12a. P. saltuensis ssp. saltuensis

1b.  Anthers 0.6–0.9 (–1) mm long; lemmas broad-acute to shortly truncate at apex [Fig. 263], the keel and lateral margins of lemma forming an apical angle of 42–82 degrees, firm at the apex, the scarious tip absent or up to 0.25 mm long; upper ligules mostly 2–4.6 mm long 
… 12b. P. saltuensis ssp. languida (A.S. Hitchc.) A. Haines

Subspecies saltuensis is known from CT, MA, ME, NH, RI, VT. Subspecies languida is known from CT, MA, RI, VT and is of regional conservation concern.

Native to North America?

Yes

Sometimes confused with

Poa alsodes:
branches of the panicle 4–8 per node and lemmas pubescent or scabrous on the keel (vs. P. saltuensis, with branches of the panicle mostly 2 per node and lemmas glabrous on the keel).

Synonyms

  • Poa saltuensis Fern. & Wieg. var. microlepis Fern.

Family

Poaceae

Genus

Poa