Asclepias syriaca — common milkweed

Characteristics

• 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 some other type of opening

  Calyx growth after flowering

  the calyx does not grow to cover or partially cover the fruit

  Calyx symmetry

  there are two or more ways to evenly divide the calyx (the calyx is radially symmetrical)

  Carpel hairs

  the carpels have hairs, but they are not thick and woolly

  Carpels fused

  the carpels are fused to one another

  Cilia on petals

  the petal margins do not have cilia

  Cleistogamous flowers

  there are no cleistogamous flowers on the plan

  Corolla palate

  no

  Corona lobe length

  4–5 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 appearance

  the flowers appear after the leaves have appeared

  Flower description

  the flower has a superior ovary, and lacks a hypanthium

  Flower diameter

  3–6 mm

  Flower orientation

  • the flower bends downwards or hangs downwards
  • the flower points upwards or is angled outwards

  Flower petal color

  • blue to purple
  • green to brown
  • pink to red

  Flower reproductive parts

  the flower has both pollen- and seed-producing parts

  Flower symmetry

  there are two or more ways to evenly divide the flower (the flower is radially symmetrical)

  Flowers sunken into stem

  no

  Form of style

  the flower has two or more completely separate styles

  Fringed petal edges

  the petals are not fringed

  Fused stamen clusters

  there is one cluster of fused stamens

  Fusion of sepals and petals

  the petals or the sepals are fused into a cup or tube

  Horns in hoods (Asclepias)

  the corona horns are shorter than, or equal in length to, the corona hoods

  Hypanthium

  the flower does not have a hypanthium

  Hypanthium length

  0 mm

  Inflorescence one-sided

  the flowers are arrayed in a spiral around the inflorescence axis or branches, or occur singly, or in several ranks

  Inflorescence type

  the inflorescence is a simple umbel (with an axis so short it appears the flowers all originate from the same point)

  Inflorescence width

  50–100 mm

  Inner tepals (Rumex)

  NA

  Length of flower stalk

  30–60 mm

  Length of peduncle

  50–100 mm

  Marks on petals

  there are no noticeable marks on the petals

  Nectar spur

  the flower has no nectar spurs

  Number of carpels

  2

  Number of pistils

  2

  Number of sepals, petals or tepals

  there are five petals, sepals, or tepals in the flower

  Number of styles

  2

  Ovary position

  the ovary is above the point of petal and/or sepal attachment

  Perianth shape

  the perianth is rotate (platter-shaped, the corolla flattened, circular, with nearly horizontally spreading lobes)

  Petal and sepal arrangement

  the flower includes three distinct cycles of petal- or sepal-like structures

  Petal and sepal colors

  • blue to purple
  • green to brown
  • pink to red

  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 folding in bud

  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

  Petal glandular dots or scales

  no

  Petal hairs (Viola)

  NA

  Petal hairs on inner/upper surface

  there are no hairs on the inner/upper petal surface

  Petal length

  7–10 mm

  Petal length relative to sepals

  the petals are longer than the sepals

  Petal nectaries

  the petals do not have nectaries

  Petal number

  5

  Petal shape

  • the petal outline is oblong (rectangular, but with rounded ends)
  • the petal outline is ovate (widest below the middle and broadly tapering at both ends)

  Petal tip shape

  the petal tip is acute (sharply pointed)

  Petal tips (Cuscuta)

  NA

  Petal width

  3–4 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 features

  the sepals do not have any of the mentioned special features

  Sepal number

  5

  Sepal orientation

  the sepals are curved outwards and downwards from the corolla

  Sepal uniformity

  all the sepals are about the same size

  Sepals fused only to sepals

  the sepals are fused to each other (not other flower parts), at least near their bases

  Spur number

  NA

  Stamen appendages

  stamen appendages are present

  Stamen attachment

  the stamens are attached at or near the bases of the petals or tepals

  Stamen number

  5

  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

  Style relative length

  the stigma protrudes beyond the mouth of the corolla

  Surface of ovary

  • the ovary surface has no points, bumps or wrinkles
  • the ovary surface is covered with small prickles
  • the ovary surface is textured with tiny points, bumps or wrinkles

  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

  Carpel beak length

  0 mm

  Fruit (pyxis) dehiscence

  NA

  Fruit beak length

  0 mm

  Fruit cross-section

  the fruit is round in cross-section

  Fruit features (Brassicaceae)

  NA

  Fruit length

  80–110 mm

  Fruit length relative to sepals

  NA

  Fruit locules

  one

  Fruit shape

  the fruit is ovoid (egg-shaped)

  Fruit stalk orientation

  the fruits curve or droop downwards

  Fruit type (general)

  the fruit is dry and splits open when ripe

  Fruit type (specific)

  the fruit is a follicle (has one ovary that splits along one side to release the seeds)

  Fruit width

  20–30 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)

  NA

  Mericarp length

  0 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 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

  Seeds comose

  hairs are present

  Septum in fruit (Brassicaceae)

  NA

  Wings on fruit

  the fruit does not have wings on it

  prickles on fruits

  • the fruits are armed with thorns-like defensive structures
  • 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 milky and opaque, and may be white or colored

  Sap color

  the sap is white

• Growth form

  Growth form

  the plant is an herb (it has self-supporting stems)

  Horizontal rooting stem

  the plant does not have stolons

  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 caudex (the root mass is firm and hardened at the top)
  • there is a thickened taproot on the plant

• Leaves

  Bracteole edges

  NA

  Bracteole number (Apiaceae)

  0

  Bracteole shape

  NA

  Bracteoles

  there are no bracteoles on the plant

  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

  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

  opposite: there are two leaves 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 bloom

  the underside of the leaf has no noticeable bloom

  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 tangled or woolly-looking hairs

  Leaf blade length

  150–230 mm

  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 coriaceous (has a firm, leathery texture)

  Leaf blade vein pattern

  the major veins of the leaf blade branch, but do not rejoin

  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

  50–90 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 flat against the leaf surface, mostly pointing towards the leaf tip
  • 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

  5–15 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)

  Leaf tufts in axils

  there are no clusters of smaller leaves growing out of axils

  Leaf type

  the leaves are simple (i.e., lobed or unlobed but not separated into 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

  0

  Leaflet petiolules

  NA

  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 edges

  NA

  Stipule features

  NA

  Stipule fused to leaf stalk

  NA

  Stipule length

  0 mm

  Stipule shape

  NA

  Stipules

  there are no stipules on the plant

  Teeth per side of leaf blade

  0

• Place

  Habitat

  terrestrial

  New England state

  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont

  Specific habitat

  • edges of forests
  • man-made or disturbed habitats
  • meadows or fields

• Scent

  Plant odor

  the plant does not have much of a smell

• Stem, shoot, branch

  Branched tendrils

  NA

  Flowering stem cross-section

  • the flowering stem is circular, or with lots of small angles so that it is roughly circular
  • the flowering stem is roughly square

  Hair between stem nodes

  the stem has hairs between the nodes

  Hairs between stem nodes

  at least some of the hairs on the stem are tangled, matted or woolly

  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

  100–150 cm

  Stem bloom

  there is no powdery or waxy film on the stem

  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 roughness between nodes

  the stem does not feel rough

  Stem spacing

  the plant is solitary, or a few plants are growing together

  Tendril origin

  NA

  Tendrils

  the plant does not have tendrils

  Wings on stem

  the stem does not have wings on it

Wetland status

Occurs only in non-wetlands. (Wetland indicator code: UPL)

In New England

From Flora Novae Angliae dichotomous key