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- Lycopus asper
Lycopus asper — western water-horehound
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Facts
Western water-horehound is native to western and central North America, but its range has been exapnding and it is now found as an introduced species in new areas including New England, where it occurs in marshes and shorelines in Massachusetts.
Habitat
Marshes, 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.
Found this plant? Take a photo and post a sighting.
Characteristics
- Habitat
- wetlands
- New England state
- Massachusetts
- Flower petal color
- white
- Leaf type
- the leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
- Leaf arrangement
- opposite: there are two leaves per node along the stem
- Leaf blade edges
-
- the edge of the leaf blade has lobes, or it has both teeth and lobes
- the edge of the leaf blade has teeth
- Flower symmetry
-
- there are two or more ways to evenly divide the flower (the flower is radially symmetrical)
- there is only one way to evenly divide the flower (the flower is bilaterally symmetrical)
- Number of sepals, petals or tepals
- there are five petals, sepals, or tepals in the flower
- Stamen number
- 1 or 2
- Fruit type (general)
- the fruit is dry but does not split open when ripe
- Fruit length
- 1.6–2.1 mm
-
Clonal plantlets
- Bulbils
- the plant does not appear to have bulbils
- Bulblets replace flowers
- there are no bulblets where the flowers are located
-
Flowers
- Calyx symmetry
- there are two or more ways to evenly divide the calyx (the calyx is radially symmetrical)
- Carpels fused
- the carpels are fused to one another
- Cleistogamous flowers
- there are no cleistogamous flowers on the plan
- Corolla palate
- no
- Corona lobe length
- 0 mm
- Epicalyx
- the flower does not have an epicalyx
- Epicalyx number of parts
- 0
- Filament surface
- the filament is smooth, with no hairs or scales
- Flower description
- the flower has a superior ovary, and lacks a hypanthium
- Flower petal color
- white
- Flower reproductive parts
-
- the flower has both pollen- and seed-producing parts
- the flower has either only pollen- or only seed-producing parts
- Flower symmetry
-
- there are two or more ways to evenly divide the flower (the flower is radially symmetrical)
- there is only one way to evenly divide the flower (the flower is bilaterally symmetrical)
- Flowers sunken into stem
- no
- Form of style
- the style is unbranched, but it has two or more narrow appendages that are part of the stigma
- Fused stamen clusters
- NA
- Horns in hoods (Asclepias)
- NA
- Hypanthium
- the flower does not have a hypanthium
- Inflorescence one-sided
- the flowers are arrayed in a spiral around the inflorescence axis or branches, or occur singly, or in several ranks
- Inner tepals (Rumex)
- NA
- Nectar spur
- the flower has no nectar spurs
- Number of carpels
- 2
- Number of pistils
-
- 1
- 4
- Number of sepals, petals or tepals
- there are five petals, sepals, or tepals in the flower
- Number of styles
- 1
- Ovary position
- the ovary is above the point of petal and/or sepal attachment
- Petal and sepal arrangement
- the flower includes two cycles of petal- or sepal-like structures
- Petal and sepal colors
- white
- Petal appearance
- the petals are thin and delicate, and pigmented (colored other than green or brown)
- Petal folds or pleats
- the petals of the flower do not have folds or plaits
- Petal hairs (Viola)
- NA
- Petal number
- 5
- Petal tips (Cuscuta)
- NA
- Reproductive system
- all the flowers have both carpels and stamens (synoecious)
- Scales inside corolla
- no
- Sepal and petal color
- the sepals are different from the petals
- Sepal appendages
- the sepals do not have appendages on them
- Sepal appendages (Oenothera)
- NA
- Sepal number
- 5
- Stamen attachment
- the stamens are attached at or near the bases of the petals or tepals
- Stamen number
- 1 or 2
- Stamen position relative to petals
- NA
- Stamen relative length
- anything
- Stamens fused
- the stamens are not attached to one another
- Staminodes
- the flower has staminodes
- Stigma position
- the stigmas are positioned at the tip of the style
- Style petal-like
- the styles are not petal-like
- Umbel flower reproductive parts
- NA
- Upper lip of bilabiate corolla
-
- NA
- the upper lip of the bilabiate corolla has one lobe
-
Fruits or seeds
- Achene relative orientation
- NA
- Achene shape
- NA
- Achene surface (Polygonum)
- NA
- Achene type
- NA
- Berry color
- NA
- Capsule color (Viola)
- NA
- Capsule ribs
- NA
- Capsule splitting
- NA
- Fruit (pyxis) dehiscence
- NA
- Fruit beak length
- 0 mm
- Fruit features (Brassicaceae)
- NA
- Fruit length
- 1.6–2.1 mm
- Fruit locules
- four
- Fruit type (general)
- the fruit is dry but does not split open when ripe
- Fruit type (specific)
- the fruit is a schizocarp (when dry it splits into sections, each holding one or more seeds)
- Legumes (Fabaceae)
- NA
- Mericarp length
- 1.3–1.8 mm
- Mericarp segment shape (Desmodium)
- NA
- Other markings on berry
- NA
- Ovary stipe
- the ovary or fruit does not have a stipe
- Placenta arrangement
- the plant has axile placentation, in which the ovules are attached where the septa of a compound ovary are united, usually on the central axis, or to the septa themselves
- Rows of seeds in fruit (Brassicaceae)
- NA
- Schizocarpic fruit compression
- the fruit is not flattened
- Schizocarpic fruit segments
- 4
- Seed number
- 1–4
- Septum in fruit (Brassicaceae)
- NA
- Wings on fruit
- the fruit does not have wings on it
- prickles on fruits
- the fruits do not have thorn-like defensive structures
-
Glands or sap
- Glands on leaf blade
- the leaf blades have glandular dots or scales
- Sap
- the sap is clear and watery
- Sap color
- the sap is clear
-
Growth form
- Growth form
- the plant is an herb (it has self-supporting stems)
- Lifespan
- the plant lives more than two years
- Parasitism
- the plant is not parasitic
- Plant color
- the leaves or young stems of the plant are green
- Plants darken when dry
- no
- Spines on plant
- the plant has no spines
- Underground organs
-
- the plant has a rhizome (a horizontal underground stem with roots growing from it)
- the plant has one or more swollen storage organs underground, such as bulbs, tubers or corms
-
Leaves
- Bracteole number (Apiaceae)
- 0
- Bracts in plantain (Plantago)
- NA
- Final leaf segment length (compound lvs only)
- 0 mm
- Final leaf segment length to width ratio (compound lvs only)
- 0
- Final leaf segment width (compound lvs only)
- 0 mm
- Hairs on underside of leaf
-
- the underside of the leaf is fuzzy or hairy
- the underside of the leaf is not hairy, or it has very few hairs
- Hairs on upper side of leaf
-
- the upper side of the leaf is fuzzy or hairy
- the upper side of the leaf is not hairy, or it has very few hairs
- Leaf arrangement
- opposite: there are two leaves per node along the stem
- Leaf blade base
-
- the leaf has a distinct leaf stalk (petiole)
- the leaf has no stalk
- Leaf blade base shape
- the base of the leaf blade is rounded
- Leaf blade edges
-
- the edge of the leaf blade has lobes, or it has both teeth and lobes
- the edge of the leaf blade has teeth
- Leaf blade length
- 40–100 mm
- Leaf blade shape
-
- the leaf blade is oblanceolate (lance-shaped, but with the widest point above the middle of the leaf blade)
- the leaf blade is oblong (rectangular but with rounded ends)
- Leaf blade surface colors
- the upper side of the leaf blade is relatively uniform in color
- Leaf blade width
- 6–35 mm
- Leaf duration
- the leaves drop off in winter (or they whither but persist on the plant)
- Leaf form
- the leaves are green, with an expanded blade and a leaf-like texture
- Leaf hair orientation
- the hairs are standing up straight or curved in different directions
- Leaf spines
- there are no spines on the leaf edges
- Leaf stalk
-
- the leaves have leaf stalks
- the leaves have no leaf stalks, but attach directly to the stem
- Leaf teeth and lobes
-
- the leaf blade margin has forward-pointing teeth
- the leaf has a row of two or more lobes on each side of the central axis
- Leaf type
- the leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
- Leaf variation
- the leaves are nearly similar in size, prominence of teeth, and length of stalks throughout the stem
- Leaflet number
- 0
- Leaves per node
- there are two leaves per node along the stem
- Pinnately compound leaf type
- NA
- Specific leaf type
- the leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
- Stipels
- NA
- Stipule features
- NA
- Stipules
- there are no stipules on the plant
-
Place
- Habitat
- wetlands
- New England state
- Massachusetts
- Specific habitat
-
- marshes
- shores of rivers or lakes
-
Scent
- Plant odor
- the plant does not have much of a smell
-
Stem, shoot, branch
- Branched tendrils
- NA
- Direction of stem hairs
- the hairs point mostly upwards to outwards
- Flowering stem cross-section
- the flowering stem is roughly square
- Hair between stem nodes
- the stem has hairs between the nodes
- Hairs between stem nodes
- the hairs on the stem are plain, without glands or branches, and not tangled
- Leaves on stem
- there is at least one full leaf above the base of the flowering stem
- Plant height
- Up to 80 cm
- Stem orientation
- the stems are upright or angled outwards
- Stem spacing
- the plant is solitary, or a few plants are growing together
- Tendril origin
- NA
- Tendrils
- the plant does not have tendrils
Wetland status
Not classified
In New England
Distribution
- Connecticut
- absent
- Maine
- absent
- Massachusetts
- present
- New Hampshire
- absent
- Rhode Island
- absent
- 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
3. Lycopus asper Greene E
western water-horehound. Lycopus lucidus Turcz. ex Benth. ssp. americanus (Gray) Hultén; L. lucidus Turcz. ex Benth. var. americanus Gray; L. maritimus Greene; Phytosalpinx aspera (Greene) Lunell • MA. Marshes, shorelines.
Native to North America?
Yes and no (some introduced)
Sometimes confused with
- Lycopus amplectens:
- corolla 5-lobed or 4-lobed with the uppermost lobe conspicuously notched and fruit +/- flat across the apex (vs. L. asper, with the corolla 4-lobed and the fruit evidently concave in the center).
Synonyms
- Lycopus lucidus Turcz. ex Benth. ssp. americanus (Gray) Hultén
- Lycopus lucidus Turcz. ex Benth. var. americanus Gray
- Lycopus maritimus Greene
- Phytosalpinx aspera (Greene) Lunell