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• All other flowering non-woody plants
• All other herbaceous, flowering dicots
• Trifolium dubium

Trifolium dubium — lesser hop clover

Facts

Lesser hop clover is a widely introduced annual legume used as forage. It may invade lawns, where it can tolerate mowing.

Habitat

Anthropogenic (man-made or disturbed habitats), meadows and fields

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 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

  2.5–3.5 mm

  Flower number

  3–25

  Flower petal color

  • green to brown
  • yellow

  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

  Fused stamen clusters

  there are two clusters of fused stamens

  Fusion of sepals and petals

  both the petals and sepals are separate and not fused

  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 length

  8–9 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 width

  Up to 8 mm

  Inner tepals (Rumex)

  NA

  Length of flower stalk

  0.2–0.5 mm

  Length of peduncle

  5–40 mm

  Marks on petals

  there are no noticeable marks on the petals

  Nectar spur

  the flower has no nectar spurs

  Number of branches in umbel

  0

  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

  Perianth shape

  NA

  Petal and sepal arrangement

  the flower includes two cycles of petal- or sepal-like structures

  Petal and sepal colors

  • green to brown
  • yellow

  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 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

  3–3.5 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

  2 mm

  Sepal number

  5

  Sepal relative length

  the sepal lobes are approximately the same length as the fused portion

  Sepal shape

  • the sepal outline is linear (extremely narrow, thread-like)
  • the sepal outline is roughly triangular

  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

  Spur length

  0 mm

  Spur number

  NA

  Stamen attachment

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

  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 length

  0.4 mm

  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

  Carpel beak length

  0 mm

  Fruit (pyxis) dehiscence

  NA

  Fruit features (Brassicaceae)

  NA

  Fruit length

  1.5–2 mm

  Fruit length relative to sepals

  the fruit is longer than its associated sepals

  Fruit locules

  one

  Fruit stalk orientation

  the fruits curve or droop downwards

  Fruit type (general)

  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)

  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

  0.8–1 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

  1 mm

  Seed number

  1

  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 only a single year or less

  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

  Bracts in plantain (Plantago)

  NA

  Final leaf segment length (compound lvs only)

  5–12 mm

  Final leaf segment length to width ratio (compound lvs only)

  1.3–2

  Final leaf segment width (compound lvs only)

  3–8 mm

  Floral bracts

  • the flower does not have bracts
  • the flower has one or more bracts associated with it

  Hairs on underside of leaf

  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 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 a distinct leaf stalk (petiole)

  Leaf blade base shape

  the base of the leaf blade is cuneate (wedge-shaped, tapers to the base with relatively straight, converging edges), or narrow

  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 has teeth
  • 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

  NA

  Leaf blade primary vein pattern

  the secondary veins branch off at intervals from the primary vein

  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 obovate (egg-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 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 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 length

  8–12 mm

  Leaf teeth and lobes

  • the edge of the leaf blade is entire (has no teeth or lobes)
  • the leaf blade margin has forward-pointing teeth

  Leaf 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 types

  NA

  Leaf variation

  the leaves are nearly similar in size, prominence of teeth, and length of stalks throughout the stem

  Leaflet number

  3

  Leaflet petiolules

  the leaflets of the compound leaf have 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

  Stipule edges

  the stipule margins have teeth on them

  Stipule features

  NA

  Stipule fused to leaf stalk

  the stipules are fused to the petioles for some or most of their length

  Stipule length

  4–5 mm

  Stipule shape

  the stipules are ovate (widest below the middle and broadly tapering at both ends)

  Stipules

  the plant has stipules

• Place

  Habitat

  terrestrial

  New England state

  • Connecticut
  • Maine
  • Massachusetts
  • Rhode Island
  • Vermont

  Specific habitat

  • 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

  Direction of stem hairs

  the hairs point mostly upwards to outwards

  Hair between stem nodes

  • the stem has hairs between the nodes
  • the stem has no hairs between the nodes

  Hairs between stem nodes

  • the hairs on the stem are plain, without glands or branches, and not tangled
  • 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

  5–40 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 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

Usually occurs in non-wetlands, but occasionally in wetlands. (Wetland indicator code: FACU)

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae