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• Dichotomous Key
• Asteraceae
• Asteraceae Group 4
• Achillea
• Achillea tomentosa

Achillea tomentosa — woolly yarrow

Facts

A low-growing plant often used in rock gardens, woolly yarrow is native to Eurasia, but can be invasive elsewhere, as it tolerates dry, low-nutrient soils. In New England, however, it has only been collected in the waste area of a nineteenth century wool carding factory in Massachusetts.

Habitat

Anthropogenic (man-made or disturbed habitats)

Characteristics

• Flowers

  Bract color

  the bracts are not colored or tinged with with pink, red or purple

  Bract cycle number

  there are three or more cycles of bracts

  Bract outer side hair type

  the bracts are hairy, with simple hairs on their outer surface

  Bract outer side hairs

  the bracts are hairy on their outer surfaces

  Bract shape

  the main bracts are lanceolate (widest above the base, then taper narrowly towards the tip)

  Bract spines

  the bracts have no spines

  Bract tip color

  the tips are a different color from the center of the bract

  Disk flower lobe number

  5

  Disk flower number

  • 11-20
  • 21-50
  • 6-10

  Disk flower reproductive parts

  the disk flower has both pollen- and seed-producing parts

  Flower head number

  each flowering stem has four or more flower heads on it

  Flower head outer flowers

  at the outer edge of the flower head, each flower has a single enlarged lobe or strap

  Flower head platform

  the base has papery scales on it

  Flower head platform surface

  the scales are slightly hairy, at least near the top

  Flower head position

  some or all the flower heads are grouped in clusters of two or more

  Flower head profile

  the disk is flat or nearly flat across the top

  Flower head shape

  • the flower head is hemispherical (like the bottom half of a sphere)
  • the sides of the flower head are roughly parallel, like a cylinder

  Flower type in flower heads

  the flower head has tubular disk flowers in the center and ray flowers, these often strap-shaped, around the periphery

  Inflorescence shape

  the inflorescence is flat-topped in profile

  Inflorescence stem

  the stem of the inflorescence is not hairy

  Ovary cross-section

  the ovary is compressed (flattened)

  Ovary hair type

  the ovary has no hairs on it

  Ovary hairs

  the ovary has no hairs on it

  Ovary lines or ribs

  • there are three lines or ribs visible on the ovary
  • there are two lines or ribs visible on the ovary

  Ovary profile

  • in profile, the ovary is oblong (roughly rectangular but rounded at the ends)
  • in profile, the ovary is roughly egg-shaped, but widest above the middle

  Peduncle length

  2–5 mm

  Ray flower color

  yellow

  Ray flower reproductive parts

  the ray flowers have carpels or stamens, but not both

  Ray flowers

  • 1-5
  • 6-10

  Ray length

  1.2–2 mm

  Reproductive system

  some of the flowers on the plant have only carpels or stamens, while others have both carpels and stamens

  Style branch number

  the style has two branches

  Style branches

  the style branch is wider at the tip and has a flattened end, or the style branches are wider at the tips and have flattened ends

  Width of flower head base

  2–4 mm

• Fruits or seeds

  Dispersal unit

  the seeds fall off or are dispersed separately from one another

  Number of pappus parts

  0

  Ovary length in developed fruit

  1–2 mm

  Seed hair tuft bases

  NA

  Seed hair tuft color

  NA

  Seed hair tuft details

  NA

  Seed hair tuft length

  0 mm

  Seed hair tuft tips

  NA

  Seed hairs uniform

  NA

  Seed tuft scale number

  0

  Seed tuft type

  there is no pappus on the ovary

  Tuft or plume on fruit

  there is no plume, or the plume is made up of scales, awns, a crown, or a rim

• Glands or sap

  Sap

  the sap is clear and watery

• Growth form

  Growth form

  the plant has one or more free-standing stems

  Plant lifespan

  the plant is perennial, it shows evidence of previous year's leaves, stems or stem bases

  Spines on plant

  the plant has no spines

  Underground organs

  the plant has a rhizome (a horizontal underground stem with roots growing from it)

• Leaves

  Final leaf segment width (compound lvs only)

  Up to 1 mm

  Hairs on underside of leaf blade

  the underside of the leaf is fuzzy or hairy

  Hairs on upper side of leaf blade

  the upper side of the leaf is fuzzy or hairy

  Leaf arrangement

  alternate: there is one leaf per node along the stem

  Leaf blade base

  • the leaf has a distinct petiole
  • the leaf has no 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 edges

  the edge of the leaf blade has teeth

  Leaf blade flatness

  NA

  Leaf blade hairs

  the leaf blade has tangled or woolly-looking hairs

  Leaf blade length

  Up to 80 mm

  Leaf blade shape

  • the leaf blade is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
  • the leaf blade is linear (very narrow with more or less parallel sides)

  Leaf blade veins

  the leaf blade has one main vein running from the base towards the tip

  Leaf disposition

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

  Leaf spines

  there are no spines on the leaf edges

  Leaf stalk

  • the leaves have leaf stalks
  • the leaves have no leaf stalks, but attach directly to the stem

  Leaf tip extension

  NA

  Leaf type

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

  Leaflet number

  At least 15

  Specific leaf type

  • the leaf has a row of two or more lobes on each side of the central axis
  • the leaf has a row of two or more lobes on each side of the central axis, and each lobe itself has rows of lobes on each side of the lobe's central axis

• Place

  Habitat

  terrestrial

  New England state

  Massachusetts

  Specific habitat

  man-made or disturbed habitats

• Scent

  Plant odor

  the plant has a pleasant odor, such as licorice, fruit or resin

• Stem, shoot, branch

  Leaves on stem

  there is at least one full leaf above the base of the flowering stem

  Stem internode hair direction

  the hairs point mostly upwards to outwards

  Stem internode hair type

  • at least some of the hairs on the stem have glands
  • the hairs on the stem are plain, without glands or branches, and not tangled

  Stem internode hairs

  the stem has hairs between the nodes

Wetland status

Not classified

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae