- You are here:
- Dichotomous Key
- Alismataceae
- Sagittaria
- Sagittaria engelmanniana
Sagittaria engelmanniana — Engelmann's arrowhead
Copyright: various copyright holders. To reuse an image, please click it to see who you will need to contact.
Facts
Engelmann's arrowhead can be found in acid waters of marshes, coastal plain ponds and peatlands. It is named after George Engelmann (1809-1884), a German botanist and physician, who settled in Missouri and described hundreds of North American plants.
Habitat
Bogs, lacustrine (in lakes or ponds), 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
-
- aquatic
- wetlands
- New England state
-
- Connecticut
- Massachusetts
- Rhode Island
- Vermont
- Leaf arrangement
- basal: the leaves are growing only at the base of the plant
- Leaf blade shape
-
- the leaf blade is cordate (heart-shaped with backward-facing rounded lobes), or sagittate (arrow-shaped with backward-facing pointed lobes)
- the leaf blade is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
- Leaf blade length
- 45–100 mm
- Flower petal color
- white
- Flower petal length
- 8–12 mm
- Petal fusion
- the perianth parts are separate
- Inflorescence type
- the inflorescence is a raceme (a long unbranched stem with stalked flowers growing along it)
- Ovary position
- the ovary is above the point of petal and/or sepal attachment
- Fruit type (specific)
- the fruit is an achene (dry, usually 1-seeded, does not separate or split open at maturity)
- Fruit length
- 2.4–4 mm
-
Clonal plantlets
- Axillary bulblets
- there are no bulblets being produced in axils
-
Flowers
- Anther attachment
- the anther is attached by its base to the filament
- Anther color
- the anthers show no hint of a pink, reddish or purplish tint
- Bulblets replace flowers
- there are no bulblets where the flowers are located
- Carpels fused
- the carpel is solitary or (if 2 or more) the carpels are not fused to one another
- Filament surface
- the filament surface has no hairs or scales on it
- Flower bract length
- 5–25 mm
- Flower bracts
- there are bracts associated with the flower
- Flower orientation
- the flowers point upward or spread or curve outward
- Flower petal color
- white
- Flower petal length
- 8–12 mm
- Flower shape
- the flower is flattened or platter-shaped
- Flower symmetry
- there are two or more ways to evenly divide the flower (the flower is radially symmetrical)
- Form of style
- the flower has two or more completely separate styles
- Fringed petal edges
- the petals are not fringed
- Hairs on flower stalk
- the flower stalk has no hairs on it
- Inflorescence hair glands
- the axis of the inflorescence has no hairs on it
- Inflorescence length
- 50–140 mm
- Inflorescence type
- the inflorescence is a raceme (a long unbranched stem with stalked flowers growing along it)
- Inflorescence width
- 20–40 mm
- Length of flower stalk
- 5–35 mm
- Length of peduncle
- 200–380 mm
- Marks on petals
-
- the petals have spots or streaks on them
- there are no noticeable marks on the petals
- Nectar spur
- the flower has no nectar spurs
- Number of carpels
- At least 3
- Number of pistils
- 6 or more
- Number of sepals and/or petals
- there are three 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 appearance
- the petals are thin and delicate, and pigmented (colored other than green or brown)
- Petal base
- the petal narrows gradually or does not narrow at the base
- Petal fusion
- the perianth parts are separate
- Petal hairs on inner/upper surface
- there are no hairs on the inner/upper petal surface
- Petal nectaries
- the petals do not have nectaries
- Sepal appearance
- the sepals resemble leaves in color and texture
- Sepal length
- 4–7 mm
- Sepal orientation
- the sepals are curved outwards and downwards
- Sepals fused only to sepals
- the sepals are separate from one another
- Spathe
- the plant does not have a spathe
- Spathe form
- NA
- Spathe length
- 0 mm
- Stamen number
- 13 or more
- Stamen position relative to petals
- NA
- Stamen types
- the stamens within a cycle are all similar
- Stamens fused
- the stamens are not fused to one another
- Stamens fused outwards
- the stamens are not fused to the petals or tepals
- Style petal-like
- the style is not broad and flattened like a petal
- Tepals
- the petals and sepals are different in size and color
-
Fruits or seeds
- Berry color
- NA
- Capsule ridges
- NA
- Fruit beak length
- 0.7–2.1 mm
- Fruit compartments
- there is only one locule in the fruit
- Fruit cross-section
- the fruit is at least somewhat flattened
- Fruit length
- 2.4–4 mm
- Fruit stalk orientation
- the fruits point upward or spread or curve outward
- Fruit type (general)
- the fruit is dry but does not split open when ripe
- Fruit type (specific)
- the fruit is an achene (dry, usually 1-seeded, does not separate or split open at maturity)
- Fruit width
- 1.5–3.8 mm
- Other markings on berry
- NA
-
Glands or sap
- Sap
- the sap is milky and opaque, and may be white or colored
-
Growth form
- Lifespan
- the plant lives more than two years
- Root septa
- the roots have transverse septa
- Underground organs
- the plant has one or more swollen storage organs underground, such as bulbs, tubers or corms
-
Leaves
- Hairs on underside of leaf blade
- the underside of the leaf is not hairy, or has very few hairs
- Hairs on upper side of leaf blade
- the upper side of the leaf is not hairy, or has very few hairs
- Leaf arrangement
- basal: the leaves are growing only at the base of the plant
- Leaf blade basal lobes
- the leaf blades are lobed at their bases
- Leaf blade base
- the leaf has a distinct leaf stalk (petiole)
- Leaf blade base shape
- The base of the leaf blade is cordate (heart-shaped, with rounded lobes) or sagittate (arrow-shaped, with pointed, backward-facing lobes)
- Leaf blade bloom
- the underside of the leaf blade has no noticeable waxy or powdery bloom
- Leaf blade cross-section
- the leaf blade is more or less flat in cross-section
- Leaf blade faces
- both surfaces of the leaf blade are exposed
- Leaf blade form
- Fully-formed (i.e., expanded), +/- green leaf blades are found somewhere on the plant
- Leaf blade length
- 45–100 mm
- Leaf blade orientation
- the upper surface of the leaf blade faces the stem of the plant
- Leaf blade shape
-
- the leaf blade is cordate (heart-shaped with backward-facing rounded lobes), or sagittate (arrow-shaped with backward-facing pointed lobes)
- the leaf blade is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
- Leaf blade surface colors
- the upper side of the leaf blade is relatively uniform in color
- Leaf blade tip
-
- the tip of the leaf blade is acute (sharply pointed)
- the tip of the leaf blade is rounded, with no point
- Leaf blade veins
- the lateral veins are parallel or slightly arched in the direction of the tip
- Leaf blade width
- 2–20 mm
- Leaf stalk length
- 100–400 mm
- Leaf type
- the leaves are simple (i.e., lobed or unlobed but not separated into leaflets
- Leaflet number
- 0
- Stipule twining
- NA
- Stipules
- there are no stipules on this plant
-
Place
- Habitat
-
- aquatic
- wetlands
- New England state
-
- Connecticut
- Massachusetts
- Rhode Island
- Vermont
- Specific habitat
-
- bogs
- in lakes or ponds
- marshes
- shores of rivers or lakes
-
Scent
- Plant odor
- the leaves have no particular smell
-
Stem, shoot, branch
- Flowering stem growth form
- the flowering stem is held upright
- Flowering stem leaves
- there are no true leaves on the flowering stem
- Stem hairs
- the stem is nearly or completely hairless
Wetland status
Occurs only in wetlands. (Wetland indicator code: OBL)
In New England
Distribution
- Connecticut
- present
- Maine
- absent
- Massachusetts
- present
- New Hampshire
- absent
- Rhode Island
- present
- Vermont
- present
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
- Massachusetts
- fairly widespread (S-rank: S4)
- Vermont
- historical (S-rank: SH)
From Flora Novae Angliae dichotomous key
2. Sagittaria engelmanniana J.G. Sm. N
Engelmann’s arrowhead. CT, MA, RI, VT. Acid water of marshes, coastal plain ponds, and peatlands. The occurrence in VT (Lake Champlain) is unusual.
Native to North America?
Yes
Sometimes confused with
- Sagittaria latifolia:
- bracts of inflorescence thin and with margins connate 25% or more of their total length and achenes with 0 or 1 facial wing (vs. S. engelmanniana, with bracts of inflorescence thick and herbaceous, distinct or with margins connate less than 25% of their total length and achenes with 1–3 facial wings).