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- Poaceae Group 4
- Poa
- Poa saltuensis
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
Native: indigenous.
Non-native: introduced (intentionally or unintentionally); has become naturalized.
County documented: documented to exist in the county by evidence (herbarium specimen, photograph). Also covers those considered historical (not seen in 20 years).
State documented: documented to exist in the state, but not documented to a county within the state. Also covers those considered historical (not seen in 20 years).
Note: when native and non-native populations both exist in a county, only native status is shown on the map.
Found this plant? Take a photo and post a sighting.
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
-
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.