Triplasis purpurea — purple sandgrass
![Leaves: Triplasis purpurea. ~ By John Hilty. ~ Copyright © 2024 John Hilty. ~ john[at]illinoiswildflowers.info ~ Illinois Wildflowers - www.illinoiswildflowers.info/index.htm](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Poaceae/triplasis-purpurea-le-jhilty.jpg)
![Stems and sheaths: Triplasis purpurea. ~ By Mary Barkworth. ~ Copyright © 2024 Mary Barkworth. ~ Mary.Barkworth[at]usu.edu ~ Manual of Grasses for North America](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Poaceae/triplasis-purpurea-purpurea-ss-mbarkworth1.jpg)
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Facts
Purple sandgrass is native to the eastern and central United States, and is an annual grass of shifting dunes. In New England it inhabits the upper sections of sandy beaches along the Atlantic coast, as well as occasionally further inland on sandy soils. It has an unusual feature for a grass: in addition to its conventional wind-pollinated flowers, it possesses cleistogamous (closed, self-fertilizing) flowers on spikelets tucked within the leaf sheaths.
Habitat
Coastal beaches (sea beaches), dunes
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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enlargeCharacteristics
- Habitat
- terrestrial
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Leaf blade width
- 1–5 mm
- Inflorescence branches
- the flowers are attached to branches rather than to the main axis of the inflorescence
- Spikelet length
- 6.5–9 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
- 0–2 mm
- Leaf sheath hair type
- there are no hairs on the surface of the leaf sheath
- Leaf ligule length
- 0.5–1 mm
-
Flowers
- Awn on glume
- the glume has no awn
- Glume relative length
- neither glume is quite as long as all of the florets
- Glume veins
- 1
- Inflorescence arrangement
- the spikelets are uniform
- Inflorescence axis orientation
-
- the inflorescence axis is arched or curved outward
- the inflorescence axis is straight
- Inflorescence branches
- the flowers are attached to branches rather than to the main axis of the inflorescence
- Inflorescence length
- 30–70 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
- the spikelets are mainly found at the nodes, in the axils of leaves, along the stem
- Lemma awn base
- the awn is attached right at the tip of the lemma
- Lemma awn length
- 0–2 mm
- Lemma awn number
-
- the lemma has no awn
- the lemma has one awn on it
- 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 split into two or more points
- Lemma vein number
- 3
- One or more florets
- there is more than one floret per spikelet
- Palea relative length
- palea is one half to fully as long as lemma
- Spikelet axis tip
- there is an extension of the spikelet axis beyond the tip of the spikelet
- Spikelet length
- 6.5–9 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 shape
- the upper glume is widest at or below the middle
-
Leaves
- Leaf auricles
- the leaves do not have auricles
- Leaf blade width
- 1–5 mm
- Leaf ligule length
- 0.5–1 mm
- Leaf ligule type
- the leaf ligule is in the form of fine hairs
- 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
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Specific habitat
-
- dunes
- sea beaches
-
Stem, shoot, branch
- Stem spacing
-
- the stems grow close together in compact clusters or tufts
- the stems grow singly or a few together (they may form diffuse colonies)
Wetland status
Not classified
In New England
Distribution
- Connecticut
- present
- Maine
- present
- Massachusetts
- present
- New Hampshire
- present
- Rhode Island
- present
- Vermont
- absent
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
- Massachusetts
- unranked (S-rank: SNR)
- New Hampshire
- historical (S-rank: SH), endangered (code: E)
From Flora Novae Angliae dichotomous key
1. Triplasis purpurea (Walt.) Chapman var. purpurea N
purple sandgrass. Triplasis intermedia Nash • CT, MA, ME, NH, RI. Upper sand beaches and dunes along the Atlantic coast, less frequently inland in sandy soils.
Native to North America?
Yes