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• Centaurea benedicta

Centaurea benedicta — blessed knapweed

Facts

Blessed knapweed is a Eurasian native now introduced throughout the world. It is widely cultivated as a medicinal herb, primarily for treating digestive and liver ailments.

Habitat

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

Characteristics

• Flowers

  Bract color

  the bracts are colored, or at least tinged with, pink, red or purple

  Bract cycle number

  there are three or more cycles of bracts

  Bract shape

  • the main bracts are lanceolate (widest above the base, then taper narrowly towards the tip)
  • the main bracts are ovate (egg-shaped)

  Bract spines

  there is one spine with branches, at the tip of the bract

  Bract texture

  the bracts have a similar texture to a leaf

  Bract tip color

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

  Bract tip extension appearance

  the projections from the bract tips have further projections from their edges, like a fringe

  Bract tip extension edge

  there are projections from the bract tips

  Bract tip orientation

  the tips of the bracts curve outwards and downwards from the plant

  Bracts

  the bracts in separate cycles are similar or gradually changing from the outer to inner cycles

  Disk flower color

  yellow

  Disk flower lobe number

  • 3
  • 5

  Disk flower number

  more than 50

  Disk flower reproductive parts

  • the disk flower has both pollen- and seed-producing parts
  • the disk flower has no reproductive parts

  Flower head number

  each flowering stem has only one to three flower heads on it

  Flower head outer flowers

  at the outer edge of the flower head, the flowers have no enlarged lobe or strap, but are bigger than the flowers in the center of the disk

  Flower head platform

  the base has fine, short hairs on it

  Flower head platform surface

  NA

  Flower head position

  each of the flower heads is separate on its own peduncle (stalk), not clustered in groups

  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)

  Flower type in flower heads

  the flower head has disk flowers only, and lacks the strap-shaped flowers

  Height of flower head base

  20–40 mm

  Inflorescence branching (Solidago)

  NA

  Inflorescence shape

  NA

  Inflorescence stem

  NA

  Ovary attachment

  the ovary is attached at the side near the base, rather than at the base

  Ovary beak

  there is no beak on the ovary

  Ovary cross-section

  the ovary has five or more corners in cross-section

  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 ten or more ribs visible on the ovary

  Ovary profile

  in profile, the ovary is oblong (roughly rectangular but rounded at the ends)

  Peduncle length

  At least 0 mm

  Ray flower color

  NA

  Ray flower reproductive parts

  NA

  Ray flowers

  0

  Reproductive system

  all the flowers on the plant contain both carpels and stamens

  Scale tip

  NA

  Smaller bracts at base of bracts

  there is no smaller, outer cycle of bracts

  Style branch number

  the style has two branches

  Width of flower head base

  20–25 mm

• Fruits or seeds

  Ovary length in developed fruit

  8–11 mm

  Ovary width in developed fruit

  2.7–3.2 mm

  Seed hair tuft color

  • the pappus hairs are another color
  • the pappus hairs are tan to dark brown

  Seed hair tuft length

  2–10 mm

  Seed hair tuft tips

  the pappus hairs are slender

  Seed hairs uniform

  there are two distinct lengths of pappus hairs

  Seed tuft scale number

  0

  Seed tuft type

  the pappus is made of stiff, tapering bristles

  Top of disk flower ovary

  NA

  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

  Leaf blade glands

  the leaf blades have glandular (translucent) dots or scales

  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 annual, it lacks evidence of previous years' growth

  Spines on plant

  • the plant has no spines
  • there are spines on the plant

• Leaves

  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 lobes, or it has both teeth and lobes
  • the edge of the leaf blade has teeth

  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
  • the leaf blade has tangled or woolly-looking hairs

  Leaf blade length

  60–250 mm

  Leaf blade shape

  • the leaf blade is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
  • the leaf blade is oblanceolate (lance-shaped, but with the widest point above the middle of the leaf blade)

  Leaf blade tip

  the tip of the leaf blade is acute (sharply pointed)

  Leaf blade width

  20–60 mm

  Leaf disposition

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

  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 (i.e., lobed or unlobed but not separated into leaflets)

  Specific leaf type

  the leaf has a row of two or more lobes on each side of the central axis

• Place

  Habitat

  terrestrial

  New England state

  • Connecticut
  • Massachusetts

  Specific habitat

  • man-made or disturbed habitats
  • meadows or fields

• Stem, shoot, branch

  Flowering stem cross-section

  the flowering stem is circular, or with lots of small angles

  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 are tangled, matted or woolly

  Stem internode hairs

  the stem has hairs between the nodes

  Stem wings

  the stem does not have wings on it

Wetland status

Not classified

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae