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- Senna
- Senna hebecarpa
Senna hebecarpa — northern wild senna
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Facts
Northern wild senna was once widespread throughout New England, but has been reduced to half a dozen of the 95 documented populations. It occurs in disturbed habitats with damp soil, and despite its rarity the plant is vigorous and self-seeding in garden conditions.
Habitat
Anthropogenic (man-made or disturbed habitats), floodplain (river or stream floodplains), forest edges, meadows and fields, 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
-
- terrestrial
- wetlands
- Flower petal color
- yellow
- Leaf type
- the leaves are compound (made up of two or more discrete leaflets
- Leaf arrangement
- alternate: there is one leaf per node along the stem
- Leaf blade edges
- the edge of the leaf blade is entire (has no teeth or lobes)
- Flower symmetry
- there is no way to evenly divide the flower (the flower is asymmetrical)
- Number of sepals, petals or tepals
- there are five petals, sepals, or tepals in the flower
- Fusion of sepals and petals
-
- both the petals and sepals are separate and not fused
- the petals or the sepals are fused into a cup or tube
- Stamen number
- 7
- Fruit type (general)
-
- the fruit is dry and splits open when ripe
- the fruit is dry but does not split open when ripe
- Fruit length
- 70–120 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
- Anther attachment
- the anther is attached by its base to the filament
- Anther opening
- the anthers have small holes or openings at the tips
- Anther spurs
- the anthers do not have spurs on them
- Calyx symmetry
- there is only one way to evenly divide the calyx (the calyx is bilaterally symmetrical)
- Carpels fused
-
- NA
- the carpel is solitary or (if 2 or more) the carpels are not fused to one another
- Cleistogamous flowers
- there are no cleistogamous flowers on the plan
- Corolla morphology
- NA
- 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 a hypanthium
- Flower diameter
- 16–20 mm
- Flower number
- 9–20
- Flower orientation
- the flower points upwards or is angled outwards
- Flower petal color
- yellow
- Flower reproductive parts
- the flower has both pollen- and seed-producing parts
- Flower symmetry
- there is no way to evenly divide the flower (the flower is asymmetrical)
- Flowers sunken into stem
- no
- Form of style
- the style is narrow at the tip and unbranched
- Fused stamen clusters
- NA
- Fusion of sepals and petals
-
- both the petals and sepals are separate and not fused
- the petals or the sepals are fused into a cup or tube
- Hairs on flower stalk
- the flower stalk has hairs on it
- Hairs on inflorescence
- the axis of the inflorescence has hairs entirely without glands
- Horns in hoods (Asclepias)
- NA
- Hypanthium
- the flower has 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
- Length of flower stalk
- 12–15 mm
- Nectar spur
- the flower has no nectar spurs
- Number of carpels
- 1
- Number of pistils
- 1
- 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
- yellow
- Petal appearance
- the petals are thin and delicate, and pigmented (colored other than green or brown)
- Petal folding in bud
- the petals in bud are arranged in a cycle with edges overlapping like roof shingles (imbricate)
- Petal folds or pleats
- the petals of the flower do not have folds or plaits
- Petal hairs (Viola)
- NA
- Petal length
- 10–15 mm
- Petal number
- 5
- Petal tips (Cuscuta)
- NA
- Raceme attachment (Veronica)
- NA
- 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 color
-
- green to brown
- yellow
- Sepal length
- 5–6 mm
- Sepal number
- 5
- Sepal uniformity
- one or more of the sepals is much narrower or shorter than the others
- Sepals fused only to sepals
- the sepals are separate from one another
- Stamen morphology
- the stamens within a cycle differ in length or width
- Stamen number
- 7
- Style petal-like
- the styles are not petal-like
- Umbel flower reproductive parts
- NA
- Upper lip of bilabiate corolla
- NA
-
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
- the capsule splits by two main valves, teeth or pores
- Fruit (pyxis) dehiscence
- NA
- Fruit cross-section
- the fruit is roughly quadrangular in cross-secgtion
- Fruit features (Brassicaceae)
- NA
- Fruit length
- 70–120 mm
- Fruit length relative to sepals
- the fruit is longer than its associated sepals
- Fruit locules
- one
- Fruit shape
-
- the fruit is flat or strongly compressed
- the fruit is obloid (longer than wide and with rounded ends)
- Fruit type (general)
-
- the fruit is dry and splits open when ripe
- the fruit is dry but does not split open when ripe
- Fruit type (specific)
- the fruit is a legume (a fruit that splits into two valves, but only has a single carpel; think of a pea pod)
- Fruit width
- 5–7 mm
- Hairs on fruit
-
- the fruits are not hairy
- the fruits have hairs on them
- Legumes (Fabaceae)
- the legume has internal partitions arranged cross-wise along the fruit
- Mericarp length
- 0 mm
- Mericarp segment shape (Desmodium)
- NA
- Other markings on berry
- NA
- Placenta arrangement
- the plant has parietal placentation, where ovules develop on the wall or slight outgrowths of the wall forming broken partitions within a compound ovary
- Rows of seeds in fruit (Brassicaceae)
- NA
- Schizocarpic fruit compression
- NA
- Schizocarpic fruit segments
- 0
- Seed relative length
- the seed is about as long as it is wide
- 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 do not 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
-
Leaves
- Bracteole number (Apiaceae)
- 0
- Bracteoles
- there are no bracteoles on the plant
- Bracts in plantain (Plantago)
- NA
- Final leaf segment length (compound lvs only)
- 30–40 mm
- Final leaf segment length to width ratio (compound lvs only)
- 2.3–3.5
- Floral bracts
- the flower does not have bracts
- 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
- alternate: there is one leaf per node along the stem
- Leaf blade base
- the leaf has a distinct leaf stalk (petiole)
- Leaf blade base shape
- the base of the leaf blade is rounded
- Leaf blade edges
- the edge of the leaf blade is entire (has no teeth or lobes)
- Leaf blade primary vein pattern
- the secondary veins branch off at intervals from the primary vein
- Leaf blade shape
-
- the leaf blade is elliptic (widest near the middle and tapering at both ends)
- the leaf blade is oblanceolate (lance-shaped, but with the widest point above the middle of the leaf blade)
- Leaf blade surface colors
- the upper side of the leaf blade is relatively uniform in color
- Leaf blade texture
- the leaf blade is herbaceous (has a leafy texture)
- Leaf blade veins
- the leaf blade has one main vein running from the base towards the tip (it may or may not have secondary veins)
- 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 spines
- there are no spines on the leaf edges
- Leaf stalk
- the leaves have leaf stalks
- Leaf teeth and lobes
- the edge of the leaf blade is entire (has no teeth or lobes)
- Leaf tip
-
- the tip of the leaf blade is acute (sharply pointed)
- the tip of the leaf blade is obtuse (bluntly pointed)
- Leaf type
- the leaves are compound (made up of two or more discrete leaflets
- Leaflet number
- 6–10
- Leaves per node
- there is one leaf per node along the stem
- Pinnately compound leaf type
- the pinnately compound leaves lack a terminal leaflet (and usually have an even number of leaflets per axis)
- Specific leaf type
- the leaf has a row of two or more lobes on each side of the central axis
- Stipels
- there are no stipels at the bases of the petiolules
- Stipule features
- NA
- Stipule shape
- NA
- Stipules
- the plant has stipules
- Teeth per side of leaf blade
- 0
-
Place
- Habitat
-
- terrestrial
- wetlands
- Specific habitat
-
- edges of forests
- man-made or disturbed habitats
- meadows or fields
- river or stream floodplains
- shores of rivers or lakes
-
Stem, shoot, branch
- Branched tendrils
- NA
- Hair between stem nodes
-
- the stem has hairs between the nodes
- the stem has no hairs between the nodes
- Leaves on stem
- there is at least one full leaf above the base of the flowering stem
- Plant height
- 50–150 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
Usually occurs in wetlands, but occasionally in non-wetlands. (Wetland indicator code: FACW)
In New England
Distribution
- Connecticut
- present
- Maine
- absent
- Massachusetts
- present
- New Hampshire
- present
- Rhode Island
- present
- Vermont
- present
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
- Connecticut
- rare (S-rank: S2), threatened (code: T)
- Massachusetts
- extremely rare (S-rank: S1), endangered (code: E)
- New Hampshire
- extremely rare (S-rank: S1), endangered (code: E)
- Rhode Island
- historical (S-rank: SH), state historical (code: SH)
- Vermont
- extremely rare (S-rank: S1), threatened (code: T)
From Flora Novae Angliae dichotomous key
1. Senna hebecarpa (Fern.) Irwin & Barneby N
northern wild senna. Cassia hebecarpa Fern. • CT, MA, NH, RI, VT; also reported from ME by Kartesz (1999), but specimens are unknown. Fields, roadsides, forest borders, riparian corridors.
Native to North America?
Yes
Sometimes confused with
- Senna obtusifolia:
- gland located between or immediately below the lowest pair of leaflets, leaves with usually 3 pairs of obovate or rarely to elliptic leaflets 1.3–1.8 times as long as wide, and inflorescence of solitary or paired axillary flowers, these sometimes clustered near stem apex (vs. S. hebecarpa, with the gland located near base of petiole, leaves with mostly 6–8 pairs of elliptic to oblanceolate leaflets 2.3–3.5 times as long as wide, and inflorescence of 9- to 20-flowered axillary and terminal racemes).
Synonyms
- Cassia hebecarpa Fern.