Melissa officinalis — lemon-balm

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

  Calyx symmetry

  there is only one way to evenly divide the calyx (the calyx is bilaterally symmetrical)

  Carpels fused

  the carpels are fused to one another

  Cleistogamous flowers

  there are no cleistogamous flowers on the plan

  Corolla morphology

  • the flower has two prominent lips
  • the tube of the flower is curved upwards

  Corolla palate

  no

  Corona lobe length

  0 mm

  Epicalyx

  the flower does not have an epicalyx

  Epicalyx number of parts

  0

  Flower description

  the flower has a superior ovary, and lacks a hypanthium

  Flower length

  8–15 mm

  Flower number

  4–12

  Flower petal color

  • pink to red
  • white
  • yellow

  Flower reproductive parts

  • the flower has both pollen- and seed-producing parts
  • the flower has either only pollen- or only 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 branched above the base

  Fused stamen clusters

  NA

  Fusion of sepals and petals

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

  Horns in hoods (Asclepias)

  NA

  Hypanthium

  the flower does not have a hypanthium

  Inner tepals (Rumex)

  NA

  Nectar spur

  the flower has no nectar spurs

  Number of carpels

  2

  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

  • pink to red
  • white
  • yellow

  Petal appearance

  the petals are thin and delicate, and pigmented (colored other than green or brown)

  Petal folds or pleats

  the petals of the flower do not have folds or plaits

  Petal hairs (Viola)

  NA

  Petal hairs on inner/upper surface

  there are no hairs on the inner/upper petal surface

  Petal length

  8–10 mm

  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 length

  7–9 mm

  Sepal number

  5

  Sepal shape

  • the sepal outline is lanceolate (lance-shaped; narrow, gradually tapering from the base to the tip)
  • the sepal outline is roughly triangular

  Stamen attachment

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

  Stamen lengths differ

  the stamens are didynamous (two long stamens and two short ones)

  Stamen number

  4

  Stamen relative length

  anything

  Stamens fused

  the stamens are not attached to one another

  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

  Style relative length

  the stigma protrudes beyond the mouth of the corolla

  Umbel flower reproductive parts

  NA

  Upper lip of bilabiate corolla

  the upper lip of the bilabiate corolla has two lobes

• 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

  Fruit (pyxis) dehiscence

  NA

  Fruit beak length

  0 mm

  Fruit features (Brassicaceae)

  NA

  Fruit locules

  four

  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)

  Legumes (Fabaceae)

  NA

  Mericarp length

  1.5–2 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 axile placentation, in which the ovules are attached where the septa of a compound ovary are united, usually on the central axis, or to the septa themselves

  Rows of seeds in fruit (Brassicaceae)

  NA

  Schizocarpic fruit compression

  the fruit is not flattened

  Schizocarpic fruit segments

  4

  Seed number

  1–4

  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 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

  Spines on plant

  the plant has no spines

• Leaves

  Bracteole length

  2–5 mm

  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 (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
  • 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

  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 cordate (heart-shaped, has rounded lobes at the base)
  • the base of the leaf blade is rounded
  • the base of the leaf blade is truncate (ends abruptly in a more or less straight line as though cut off)

  Leaf blade base symmetry

  the leaf blade base is symmetrical

  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

  • the leaf blade has hairs with glands at their tips
  • the leaf blade has simple hairs with no glands, and not tangled or wooly

  Leaf blade length

  20–90 mm

  Leaf blade primary vein pattern

  the secondary veins branch off at intervals from the primary vein

  Leaf blade shape

  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 vein pattern

  the major veins form a net-like pattern due to splitting and rejoining

  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

  15–70 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 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 length

  10–40 mm

  Leaf teeth and lobes

  • the leaf blade margin has forward-pointing teeth
  • the leaf blade margin has rounded teeth

  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 simple (lobed or unlobed but not separated into leaflets)

  Leaf variation

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

  Leaflet number

  0

  Leaves per node

  there are two leaves per node along the stem

  Pinnately compound leaf type

  NA

  Specific leaf type

  the leaves are simple (lobed or unlobed but not separated into leaflets)

  Stipels

  NA

  Stipule features

  NA

  Stipules

  there are no stipules on the plant

• Place

  Habitat

  terrestrial

  New England state

  • Connecticut
  • Massachusetts
  • Rhode Island
  • Vermont

  Specific habitat

  • man-made or disturbed habitats
  • meadows or fields

• Scent

  Plant odor

  the plant has a pleasant smell, for example anise, fruit, mint or resin

• Stem, shoot, branch

  Branched tendrils

  NA

  Flowering stem cross-section

  the flowering stem is roughly square

  Hair between stem nodes

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

  Hairs between stem nodes

  at least some of the hairs on the stem have glands

  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

  20–150 cm

  Stem orientation

  the stems are upright or angled outwards

  Tendril origin

  NA

  Tendrils

  the plant does not have tendrils

Wetland status

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

In New England

From Flora Novae Angliae dichotomous key