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- Desmazeria rigida
Desmazeria rigida — fern grass
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Facts
Fern grass is native to Europe and western Asia and a visitor with scattered occurrences in North America, including New England, where it has been collected in Massachusetts and Rhode Island.
Habitat
Anthropogenic (man-made or disturbed habitats), meadows and fields
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.
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Characteristics
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Massachusetts
- Rhode Island
- Leaf blade width
- 0.5–4 mm
- Inflorescence branches
- the flowers are attached to branches rather than to the main axis of the inflorescence
- Spikelet length
- 4–10 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 no hairs on the surface of the leaf sheath
- Leaf ligule length
- 1.5–4 mm
- Anther length
- 0.4–0.5 mm
-
Flowers
- Anther length
- 0.4–0.5 mm
- 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
- the lemma is thin and flexible
- Floret number
- 4–12
- Floret types within spikelet
- all the florets within a spikelet are similar
- Glume awn length
- 0 mm
- Glume relative length
- neither glume is quite as long as all of the florets
- Glume shape
-
- the glume is V-shaped in cross-section
- the glume is flat or curved 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 branches
- the flowers are attached to branches rather than to the main axis of the inflorescence
- Inflorescence branches coming off the lowest stem node
- 1–2
- Inflorescence crowding
-
- the panicle is somewhat to very congested (crowded), and the branches may not be clearly seen without close inspection
- the panicle is somewhat to very spread out, with clearly-evident branches
- Inflorescence length
- 10–180 mm
- Inflorescence length to width ratio
- 0.8–6
- Inflorescence type (general)
- the spikelets are borne on stalks or on branches
- Inflorescence type (specific)
-
- the inflorescence is a raceme (a long unbranched stem with stalked flowers growing along it)
- the inflorescence is branched, and the branches do NOT both grow from the same side of the plant AND look like spikes
- Inflorescence width
- 12–30 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
- 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 V-shaped if you cut across the midpoint
- 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
- 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 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 narrow point (it may or may not also have an awn or teeth at the tip)
- Lemma vein number
- 5
- Lemma vein orientation
- the veins on the lemma come together near the tip
- Lower glume length
- 1.3–2 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 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
- 4–10 mm
- Spikelet number per node
- Up to 0
- Spikelet pedicel
- the spikelets have pedicels
- Spikelet pedicel length
- 0.5–1.5 mm
- Spikelet position
- the spikelets emerge from both the upper and lower halves of the inflorescence branches
- Spikelets per panicle branch
- At least 0
- 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
- 1.5–2.3 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
- Seed length
- 1.5–2 mm
-
Growth form
- Horizontal rooting stem
- no
- Lifespan
- the plant lives only a single year or less
- Rhizomes
- no
- Roots
- there are only slender roots on the plant
-
Leaves
- Basal leaves
- the plant has large or prominent tufts of leaves at the base of the flowering stem
- Leaf auricles
- the leaves do not have auricles
- Leaf basal lobe hairy
- NA
- Leaf blade cross-section
-
- the leaf blade is clearly folded or rolled inwards
- 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
- 1–12 cm
- Leaf blade texture
- the leaf blade is rough and sandpapery
- Leaf blade width
- 0.5–4 mm
- Leaf ligule length
- 1.5–4 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 no hairs on the surface of the leaf sheath
- Leaf sheath hairs
- 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
-
- terrestrial
- wetlands
- New England state
-
- Massachusetts
- Rhode Island
- Specific habitat
-
- man-made or disturbed habitats
- meadows or fields
-
Stem, shoot, branch
- Hairs at nodes
- the stem nodes are hairless or they have very sparse hairs
- Plant height
- 2–60 cm
- Stem hairs
- the stem is nearly to completely hairless
- Stem node number
- 2–5
- Stem orientation
-
- the stems are upright
- the stems trail along the ground or on other plants through most or all of their length
- the stems trail at the base, but turn upwards at the tips
- Stem spacing
- the stems grow close together in compact clusters or tufts
Wetland status
Not classified
In New England
Distribution
- Connecticut
- absent
- 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.
- Massachusetts
- not applicable (S-rank: SNA)
From Flora Novae Angliae dichotomous key
1. Desmazeria rigida (L.) Tutin E
fern grass. Catapodium rigidum (L.) C.E. Hubbard ex Doney; Poa rigida L.; Scleropoa rigida (L.) Griseb. • MA, RI. Fields, roadsides, ditches, disturbed soil.
Native to North America?
No
Sometimes confused with
- Brachypodium pinnatum:
- inflorescence a raceme and lemmas 6-11 mm long, usually pubescent (vs. D. rigida, with the inflorescence a panicle and lemmas 2-3 mm long, glabrous).
- Poa compressa:
- lemmas keeled, with a tuft of arachnoid hairs on the callus, and anthers 1.3-1.8 mm long (vs. D. rigida, with lemmas lacking a keel or weakly keeled near the apex, lacking a tuft of arachnoid hairs on the callus, and anthers 0.4-0.6 mm long).
Synonyms
- Catapodium rigidum (L.) C.E. Hubbard ex Doney
- Poa rigida L.
- Scleropoa rigida (L.) Griseb.