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 - Astragalus alpinus
 
Astragalus alpinus — alpine milk-vetch
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Facts
Alpine milk-vetch has a circumboreal distribution, and is found across northern North America. In New England it is rare and occurs in Maine, New Hampshire and Vermont on open river shores on high-pH, rocky or gravel substrate.
Habitat
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
 
- Flower petal color
 - 
                                
                                    
- blue to purple
 - white
 
 
- 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
 
- Fruit type (general)
 - the fruit is dry and splits open when ripe
 
- Fruit length
 - 8–16 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 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
 - 7–13 mm
 
- Flower number
 - 5–15
 
- Flower orientation
 - the flower points upwards or is angled outwards
 
- Flower petal color
 - 
                                
                                    
- blue to purple
 - white
 
 
- 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
 
- Length of flower stalk
 - 0.5–1.5 mm
 
- Length of peduncle
 - 30–150 mm
 
- Marks on petals
 - the petals have spots or streaks on them
 
- 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
 - white
 
 
- Petal appearance
 - the petals are thin and delicate, and pigmented (colored other than green or brown)
 
- Petal base
 - the petal narrows abruptly at the base
 
- Petal folding in bud
 - 
                                
                                    
- the petals in bud are arranged in a cycle with edges overlapping like roof shingles (imbricate)
 - the petals in bud meet exactly at the margins without overlapping (valvate)
 
 
- 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
 - 7–13 mm
 
- Petal length relative to sepals
 - the petals are longer than the sepals
 
- Petal number
 - 5
 
- Petal shape
 - the petal outline is elliptic (shaped like an ellipse; widest near the middle and tapering at both ends)
 
- Petal tip shape
 - the petal tip is retuse (with a blunt or rounded apex and a notch at the center)
 
- Petal tips (Cuscuta)
 - NA
 
- Petal width
 - 3–7.5 mm
 
- 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 auricles
 - the sepals have no auricles
 
- Sepal color
 - green to brown
 
- Sepal length
 - 4–6 mm
 
- Sepal number
 - 4–5
 
- Sepal orientation
 - the sepals are pressed against the corolla, or jutting stiffly upward
 
- Sepal relative length
 - the sepal lobes are shorter 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 number
 - 10
 
- Stamens fused
 - the stamens are attached to one another at or near their bases
 
- Staminodes
 - there are no staminodes on the flower
 
- 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
 
 - 
                        
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 triangular in cross-section
 
- Fruit features (Brassicaceae)
 - NA
 
- Fruit length
 - 8–16 mm
 
- Fruit length relative to sepals
 - the fruit is longer than its associated sepals
 
- Fruit locules
 - one
 
- Fruit shape
 - 
                                
                                    
- the fruit is ellipsoid (widest in the middle and tapering to each end)
 - the fruit is obloid (longer than wide and with rounded ends)
 
 
- Fruit stalk orientation
 - 
                                
                                    
- the fruits curve or droop downwards
 - the fruits point upward or spread or curve outward
 
 
- Fruit type (general)
 - the fruit is dry and splits 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
 - 3–4 mm
 
- 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
 - 0 mm
 
- Mericarp segment shape (Desmodium)
 - NA
 
- Other markings on berry
 - NA
 
- Ovary stipe
 - the ovary or fruit has a stipe
 
- Ovary stipe length
 - 1.5–3.5 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
 - NA
 
- Schizocarpic fruit segments
 - 0
 
- Seed length
 - 2.5–3 mm
 
- Seed number
 - 5–10
 
- Seed relative length
 - the seed is longer than it is wide
 
- Seed surface
 - the seed is smooth or without clear markings
 
- 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
 - there are spines on the plant
 
- Underground organs
 - the plant has a caudex (the root mass is firm and hardened at the top)
 
 - 
                        
Leaves
- Bracteole number (Apiaceae)
 - 0
 
- Bracteoles
 - the plant has bracteoles between the primary bracts and the flowers
 
- Bracts in plantain (Plantago)
 - NA
 
- Final leaf segment length to width ratio (compound lvs only)
 - 1.3–3.5
 
- Floral bracts
 - the flower has one or more bracts associated with it
 
- Flower bract length
 - 0.5–2 mm
 
- Hairs on leaf stalk
 - the petiole has hairs on it
 
- Hairs on underside of leaf
 - the underside of the leaf is fuzzy or hairy
 
- 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
 
- Inflated hairs on leaf
 - the leaf blade does not have inflated hairs on it
 
- Leaf arrangement
 - alternate: there is one leaf per node along the stem
 
- Leaf blade base
 - the leaf has no stalk
 
- 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 length
 - 20–80 mm
 
- 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)
 
- 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 blade width
 - 2–7 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
 - NA
 
- 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
 - 30–120 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 retuse (blunt or rounded, with a notch at the tip)
 - the tip of the leaf blade is rounded, with no point
 
 
- Leaf type
 - the leaves are compound (made up of two or more discrete leaflets
 
- Leaf variation
 - the leaves are nearly similar in size, prominence of teeth, and length of stalks throughout the stem
 
- Leaflet number
 - 15–25
 
- Leaflet petiolules
 - the leaflets of the compound leaf lack petiolules
 
- 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
 - there are no stipels at the bases of the petiolules
 
- Stipule features
 - NA
 
- Stipule fused to leaf stalk
 - the stipules are fused to the petioles for some or most of their length
 
- Stipule length
 - 1.5–6 mm
 
- Stipules
 - the plant has stipules
 
 - 
                        
Place
- Habitat
 - wetlands
 
- Specific habitat
 - shores of rivers or lakes
 
 - 
                        
Stem, shoot, branch
- Branched tendrils
 - NA
 
- Direction of stem hairs
 - NA
 
- Hair between stem nodes
 - the stem has no hairs between the nodes
 
- Hairs between stem nodes
 - the stem has no hairs between the nodes
 
- Hooked hairs on stem between nodes
 - no
 
- Leaves on stem
 - there is at least one full leaf above the base of the flowering stem
 
- Plant height
 - 0.5–10 cm
 
- Stem bloom
 - there is no powdery or waxy film on the stem
 
- Stem hair distribution
 - NA
 
- Stem orientation
 - 
                                
                                    
- the stems are upright or angled outwards
 - the stems trail at the base, but may turn upwards at the tips
 
 
- Stem roughness between nodes
 - the stem does not feel rough
 
- Stem spacing
 - the plant is growing in tufts, or compact clusters with closely spaced stems, or it is densely matted together in clumps, cushionlike
 
- Tendril origin
 - NA
 
- Tendrils
 - the plant does not have tendrils
 
- Wings on stem
 - the stem does not have wings on it
 
 
Wetland status
Occurs in wetlands or non-wetlands. (Wetland indicator code: FAC)
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
 - uncommon (S-rank: S3)
 
var. brunetianus
- Maine
 - uncommon (S-rank: S3), special concern (code: SC)
 
- New Hampshire
 - extirpated (S-rank: SX), X (code: X)
 
- Vermont
 - extirpated (S-rank: SX)
 
Subspecies and varieties
Our variety is Astragalus alpinus L. var. brunetianus Fern.
From Flora Novae Angliae dichotomous key
1. Astragalus alpinus L. var. brunetianus Fern. NC
alpine milk-vetch. Astragalus alpinus L. var. labradoricus (DC.) Fern. • ME, NH, VT. Open, gravel, cobble, and ledge river shores in regions of high-pH bedrock and/or till.
Native to North America?
Yes
Sometimes confused with
- Astragalus eucosmus:
 - principal leaves with mostly 7-15 leaflets, keel petal markedly shorter than the banner petal, and upper suture of fruit scarcely sulcate (vs. A. alpinus, with principal leaves with 15-25 leaflets, keel petal not or only slightly shorter than the banner petal, and upper suture of fruit prominently sulcate).
 - Astragalus robbinsii:
 - principal leaves with mostly 7-15 leaflets, keel petal markedly shorter than the banner petal, and upper suture of fruit scarcely sulcate (vs. A. alpinus, with principal leaves with 15-25 leaflets, keel petal not or only slightly shorter than the banner petal, and upper suture of fruit prominently sulcate).
 
Synonyms
- Astragalus alpinus L. var. labradoricus (DC.) Fern.