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- Desmodium glabellum
Desmodium glabellum — smooth tick-trefoil
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Facts
Smooth tick-trefoil is a plant of the eastern and southern United States, just barely entering New England in Connecticut, where it is very rare.
Habitat
Anthropogenic (man-made or disturbed habitats), woodlands
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
- Flower petal color
- blue to purple
- 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 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
- there are four petals, sepals, or tepals in the flower
- Fusion of sepals and petals
- the petals or the sepals are fused into a cup or tube
- Stamen number
- 10
- Stem nodes swollen
- the stem is not swollen at the nodes
- Fruit type (general)
- the fruit is dry but does not split open when ripe
-
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 opening
- the anthers have narrow slits or furrows that run lengthwise along the anthers
- 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 length
- 7–10 mm
- Flower petal color
- blue to purple
- Flower reproductive parts
- the flower has both pollen- and seed-producing parts
- Flower symmetry
- 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 narrow at the tip and unbranched
- Fused stamen clusters
- there are two clusters of fused stamens
- Fusion of sepals and petals
- the petals or the sepals are fused into a cup or tube
- 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
- Interior flower disk
- the flower does not have an interior disc
- Length of flower stalk
- 2–12 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
- there are four 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
- blue to purple
- 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
- the petals of the flower have folds or plaits on them
- Petal hairs (Viola)
- NA
- Petal length
- 6–9 mm
- Petal length relative to sepals
- the petals are longer than the sepals
- Petal number
- 5
- Petal tips (Cuscuta)
- NA
- Raceme attachment (Veronica)
- 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 appearance
- the sepals are green or brown, and leaf-like in texture
- Sepal appendages
- the sepals do not have appendages on them
- Sepal appendages (Oenothera)
- NA
- Sepal color
- green to brown
- Sepal length
- Up to 4 mm
- Sepal number
- 5
- Sepal orientation
- the sepals are slightly curved outwards from the corolla
- Sepal relative length
- the sepal lobes are longer than the fused portion
- Sepal shape
- the sepal outline is roughly triangular
- Sepal texture
- the sepals are either very thin but flexible, like a membrane, or they are leaf-like in texture
- Sepal tip shape
- the sepal tip is acute (is sharply pointed)
- Sepal uniformity
- one or more of the sepals is much narrower or shorter than the others
- Sepals fused only to sepals
- the sepals are fused to each other (not other flower parts), at least near their bases
- Stamen morphology
- the stamens within each cycle are the same
- Stamen number
- 10
- Stamens fused
- the stamens are attached to one another at or near their bases
- Staminodes
- there are no staminodes on the flower
- 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 at least somewhat flattened
- Fruit features (Brassicaceae)
- NA
- Fruit locules
- one
- Fruit shape
-
- the fruit is flat or strongly compressed
- the fruit is obloid (longer than wide and with rounded ends)
- 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 a schizocarp (when dry it splits into sections, each holding one or more seeds)
- Hair type on fruit
- the hairs on the fruits are simple (not branched), don’t have glands, and are not woolly
- Hairs on fruit
- the fruits have hairs on them
- Legumes (Fabaceae)
- the legume has none of the mentioned special features
- Mericarp length
- 3.5–8.5 mm
- Mericarp segment shape (Desmodium)
- the mericarp is roughly triangular on the lower margin
- Other markings on berry
- NA
- Ovary stipe
- the ovary or fruit has a stipe
- Ovary stipe length
- 3–5 mm
- 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
- the fruit is flattened perpendicular to the commissure
- Schizocarpic fruit segments
- 1–5
- Seed number
- 1–5
- 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
- Underground organs
- there is a thickened taproot on the plant
-
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)
- 20–80 mm
- Final leaf segment length to width ratio (compound lvs only)
- 1.5–5
- Floral bracts
- the flower has one or more bracts associated with it
- Hairs on leaf stalk
-
- the petiole has hairs on it
- the petiole has no hairs on it
- 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
- Hooked hairs on underside of leaf
- no
- 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 base symmetry
- the leaf blade base is symmetrical
- Leaf blade edges
- the edge of the leaf blade is entire (has no teeth or lobes)
- Leaf blade flatness
- the leaf is flat (planar) at the edges
- Leaf blade hairs
- the leaf blade has simple hairs with no glands, and not tangled or wooly
- Leaf blade primary vein pattern
- the secondary veins branch off at intervals from the primary vein
- Leaf blade shape
-
- the leaf blade is oblong (rectangular but with rounded ends)
- the leaf blade is ovate (widest below the middle and broadly tapering at both ends)
- 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 hair orientation
- the hairs are standing up straight or curved in different directions
- Leaf shiny
- the upper side of the leaf is dull or slightly shiny
- Leaf spines
- there are no spines on the leaf edges
- Leaf stalk
- the leaves have leaf stalks
- Leaf stalk attachment to leaf
- the petiole attaches at the basal margin of the leaf blade
- Leaf stalk base
- the petiole base is narrow where it attaches to the stem
- Leaf stalk length
- 2–5 mm
- 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
- Leaf types
- There is a gradual change in appearance of the leaves from the base (or near the base) of the plant to those from further up on the stem, with leaves progressively changing as one moves higher on the stem (often becoming shorter, or less toothed/lobed, and/or with shorter petioles).
- Leaf variation
- the leaves are nearly similar in size, prominence of teeth, and length of stalks throughout the stem
- Leaflet number
- 1–3
- Leaves per node
- there is one leaf per node along the stem
- Pinnately compound leaf type
- the pinnately compound leaves have a terminal leaflet (and usually have an odd 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
- the petiolules have stipels at their bases
- Stipule edges
-
- the stipule margins do not have teeth
- the stipule margins have teeth on them
- Stipule features
- NA
- Stipule length
- 2–6 mm
- Stipule shape
-
- the stipules are lanceolate (lance-shaped; widest below the middle and tapering at both ends)
- the stipules are triangular
- Stipules
- the plant has stipules
- Teeth per side of leaf blade
- 0
-
Place
- Habitat
- terrestrial
- Specific habitat
-
- man-made or disturbed habitats
- woodlands
-
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 circular, or with lots of small angles so that it is roughly circular
- 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
- Hooked hairs on stem between nodes
- yes
- Leaves on stem
- there is at least one full leaf above the base of the flowering stem
- Plant height
- 50–150 cm
- Stem hair distribution
- the hairs on the stem are distributed more of less uniformly
- Stem nodes swollen
- the stem is not swollen at the nodes
- Stem orientation
- the stems are upright or angled outwards
- Stem spacing
- the plant is solitary, or a few plants are growing together
- Stem succulence
- the stems are not succulent
- Tendril origin
- NA
- Tendrils
- the plant does not have tendrils
- Wings on stem
- the stem does not have wings on it
Wetland status
Not classified
In New England
Distribution
- Connecticut
- present
- Maine
- absent
- Massachusetts
- absent
- 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.
- Connecticut
- rare (S-rank: S2), special concern (code: SC)
- Massachusetts
- unranked (S-rank: SNR)
From Flora Novae Angliae dichotomous key
5. Desmodium glabellum (Michx.) DC. NC
smooth tick-trefoil. Hedysarum glabellum Michx.; Meibomia glabella (Michx.) Kuntze • CT. Woodlands, roadsides, open powerline rights-of-way. The report of this species in MA by Isely (1998) was almost certainly an error considering the manuscript is internally inconsistent (the map and text are not in agreement). The report of this species in RI by Gould et al. (1998) was based on a taxonomy that included Desmodium perplexum as a race of D. glabellum (i.e., D. perplexum does occur in RI, but D. glabellum s.s. does not).
Native to North America?
Sometimes confused with
Synonyms
- Hedysarum glabellum Michx.
- Meibomia glabella (Michx.) Kuntze