Neottia auriculata — auricled twayblade
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Facts
Auricled twayblade is a rare orchid with a restricted distribution that includes northern New England, where it is found on sandy alluvial deposits on stream banks and riparian forests. It rarely hybridizes with broad-leaved twayblade (Neottia convallarioides), producing intermediate plants.
Habitat
Bogs, fens, floodplain (river or stream floodplains), forests, shores of rivers or lakes
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
- wetlands
- New England state
-
- Maine
- New Hampshire
- Vermont
- Leaf arrangement
-
- alternate: there is one leaf per node along the stem
- opposite: there are two leaves per node along the stem
- Number of leaves on stem
-
- three
- two
- Form of lower petal
- the labellum does not have a pouch-like shape
- Lower petal outline
- the labellum is lobed but not fringed
- Main color of lower petal
-
- green to brown
- other
- white
- Nectar spur
- there are no nectar spurs on the flower
- Inflorescence type
- the inflorescence is a raceme (a long unbranched stem with stalked flowers growing along it)
- Lower petal characteristics
- the labellum is lobed
- Lower petal length
- 6–11 mm
- Sepal length
- 3–4 mm
-
Flowers
- Flower bract length
- 2–7 mm
- Flower petal color
- white
- Flower symmetry
- there is only one way to evenly divide the flower (the flower is bilaterally symmetrical)
- Flowering date
-
- August
- July
- June
- Flowers per inflorescence
- 5–20
- Form of lower petal
- the labellum does not have a pouch-like shape
- Hairs on flower stalk
- the flower stalk has no hairs on it
- Hairs on inflorescence axis
- at least some of the hairs on the main stem of the inflorescence have glands
- Inflorescence length
- 20–100 mm
- Inflorescence type
- the inflorescence is a raceme (a long unbranched stem with stalked flowers growing along it)
- Labellum position
- the labellum is in the lower position on the flower
- Length of flower stalk
- 2.5–5 mm
- Length of narrowed base of lower petal
- 0 mm
- Lower petal characteristics
- the labellum is lobed
- Lower petal length
- 6–11 mm
- Lower petal outline
- the labellum is lobed but not fringed
- Lower petal strongly red-veined
- no
- Main color of lower petal
-
- green to brown
- other
- white
- Nectar spur
- there are no nectar spurs on the flower
- Nectar spur length
- 0 mm
- Number of stamens
- 1
- Orientation of side petals
-
- the lateral petals are angled steeply upwards
- the lateral petals slant outward
- Self-pollinating flowers
- there are no cleistogamous flowers on this plant
- Sepal length
- 3–4 mm
- Sepals fused only to sepals
- the sepals are separate from one another
- Spots on lower petal
- no
- Spur opening membrane
- NA
- Spur opening shape
- NA
-
Fruits or seeds
- Seed capsule orientation
- the capsule points upwards or is angled outwards
-
Growth form
- Plant green or not
- the plant is chlorophyllous (it has green parts)
- Roots
- the rhizomes do not resemble coral
- Underground organs
- there are only slender roots on the plant
-
Leaves
- Bract relative length
- the bract is shorter than the associated flower
- Features of leaves
- the leaf does not have any of the mentioned special features
- Leaf arrangement
-
- alternate: there is one leaf per node along the stem
- opposite: there are two leaves per node along the stem
- Leaf blade edges
- the edges of the leaf blade have no teeth
- Leaf blade length
- 25–60 mm
- Leaf blade length to width ratio
- 1.4–1.7
- Leaf blade shape
-
- the leaf blade is elliptic (widest near the middle and tapering at both ends)
- the leaf blade is orbicular (roughly circular, as wide as long)
- the leaf blade is ovate (widest below the middle and broadly tapering at both ends)
- Leaf blade tip
- the tip of the leaf blade is obtuse (bluntly pointed)
- Leaf blade width
- 15–42 mm
- Leaves during flowering
- there are leaves on the plant when it is flowering
- Number of leaves on stem
-
- three
- two
-
Place
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Maine
- New Hampshire
- Vermont
- Specific habitat
-
- bogs
- fens
- forests
- river or stream floodplains
- shores of rivers or lakes
Wetland status
Usually occurs in wetlands, but occasionally in non-wetlands. (Wetland indicator code: FACW)
In New England
Distribution
- Connecticut
- absent
- Maine
- present
- Massachusetts
- absent
- New Hampshire
- present
- Rhode Island
- absent
- Vermont
- present
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
- Maine
- rare (S-rank: S2), threatened (code: T)
- New Hampshire
- extremely rare (S-rank: S1), endangered (code: E)
- Vermont
- extremely rare (S-rank: S1)
From Flora Novae Angliae dichotomous key
1. Neottia auriculata (Wieg.) Szlach. NC
auricled twayblade. Bifolium auriculatum (Wieg.) Nieuwl.; Listera auriculata Wieg.; Ophrys auriculata (Wieg.) House • ME, NH, VT. Stream banks, riparian forests of small to large rivers, often in alluvium and commonly associated with Alnus incana, rarely in open peatlands.
1×3. Neottia auriculata × Neottia convallarioides → Neottia ×veltmanii (Case) Baumbach is a rare twayblade hybrid known from ME but is to be expected elsewhere in northern New England. It is usually associated with one or both parents (i.e., it is not typically found alone). It has the basally narrowed labellum of N. convallarioides and, like that species, has stipitate glands on the pedicels and ovary. However, the stipitate glands on these parts are shorter and sparser than those of the inflorescence axis (in N. convallarioides, the stipitate glands are similar in length and ± similar in density on the glandular portions of the inflorescence). Further, the hybrid shows a small pair of outward pointing auricles at the very base of the lip (rather than a small pair of teeth distal to the narrow portion of the labellum).
Native to North America?
Yes
Sometimes confused with
- Neottia convallarioides:
- labellum narrowed at the base, usually bearing a pair of small teeth at the base, and axis of the inflorescence, pedicels, and ovary stipitate-glandular (vs. N. auriculata, with the labellum maintaining its width and not narrowed at the base, bearing a pair of retrorse auricles at the base, and pedicels and ovary glabrous, only the axis of the inflorescence stipitate-glandular).
Synonyms
- Bifolium auriculatum (Wieg.) Nieuwl.
- Listera auriculata Wieg.
- Ophrys auriculata (Wieg.) House