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Hypericum prolificum — shrubby St. John's-wort

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Facts

Shrubby St. John's-wort produces "prolific" numbers of stamens on its flowers, which are so numerous they almost obscure the yellow petals during peak bloom time in July. This adaptable shrub, with peeling brown bark, is a drought-tolerant member of many gardens south and west of New England. In our region, it inhabits man-made habitats and is not considered native, even though it is listed as endangered in neighboring New York and New Jersey.

Habitat

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

New England distribution

Adapted from BONAP data

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North America distribution

Adapted from BONAP data

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Characteristics

Habitat
terrestrial
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont
Growth form
the plant is a shrub (i.e., a woody plant with several stems growing from the base)
Leaf type
the leaf blade is simple (i.e., lobed or unlobed but not separated into leaflets)
Leaves per node
there are two leaves per node along the stem
Leaf blade edges
the edge of the leaf blade has no teeth or lobes
Leaf duration
the leaves drop off in winter (or they wither but persist on the plant)
armature on plant
the plant does not have spines, prickles, or thorns
Leaf blade length
30–80 mm
Leaf blade width
4–15 mm
Leaf stalk
the leaves have leaf stalks
Fruit type (general)
the fruit is dry and splits open when ripe
Bark texture
  • the bark of an adult plant is thin and smooth
  • the bark of an adult plant peels off easily or hangs off
Twig winter color
  • brown
  • orange
Show all characteristics

  • Buds or leaf scars

    Bud scar shape (Fraxinus)
    NA

  • Flowers

    Carpels fused
    the carpels are fused to one another
    Enlarged sterile flowers
    there are no enlarged sterile flowers on the plant
    Flower petal color
    • orange
    • yellow or green
    Flower symmetry
    there are two or more ways to evenly divide the flower (the flower is radially symmetrical)
    Hairs on ovary (Amelanchier)
    NA
    Hypanthium present
    the flower does not have a hypanthium
    Inflorescence type
    • the inflorescence has only one flower on it
    • the inflorescence is a fascicle (compact cluster of flowers)
    Number of pistils
    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 appearance
    the petals are thin and delicate, and pigmented (colored other than green or brown)
    Petal fusion
    the perianth parts are separate
    Sepal cilia (Ilex)
    NA
    Stamen number
    13 or more

  • Fruits or seeds

    Berry color
    NA
    Fruit tissue origin
    there are no flower parts that form part of the fruit
    Fruit type (general)
    the fruit is dry and splits open when ripe
    Fruit type (specific)
    the fruit is a capsule (splits along two or more seams, apical teeth or pores when dry, to release two or more seeds)
    Nut with spines (Fagaceae)
    NA
    Wings on fruit
    there are no wings on the fruit

  • Glands or sap

    Sap color
    the sap is clear and watery
    Stalked glands on fruit (Rosa)
    NA

  • Growth form

    Growth form
    the plant is a shrub (i.e., a woody plant with several stems growing from the base)

  • Leaves

    Hairs on upper side of leaf blade
    the upper side of the leaf is not hairy, or has very few hairs
    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 no teeth or lobes
    Leaf blade edges (Acer)
    NA
    Leaf blade hairs
    at least some of the hairs on the leaf blade have glands at their tips
    Leaf blade length
    30–80 mm
    Leaf blade scales
    there are no scales on the leaf blades
    Leaf blade shape
    • the leaf blade is elliptic (widest near the middle and tapering at both ends)
    • the leaf blade is linear (very narrow with more or less parallel sides)
    • the leaf blade is oblong (rectangular but with rounded ends)
    Leaf blade translucent dots
    the leaf blade has translucent dots on it
    Leaf blade width
    4–15 mm
    Leaf duration
    the leaves drop off in winter (or they wither but persist on the plant)
    Leaf lobe tips (Quercus)
    NA
    Leaf midrib glands
    the midrib of the leaf blade lacks glands on the upper surface
    Leaf stalk
    the leaves have leaf stalks
    Leaf stalk nectaries
    there are no nectaries on the leaf stalk
    Leaf teeth
    the edge of the leaf blade is entire (has no teeth or lobes)
    Leaf teeth hairs (Carya)
    NA
    Leaf type
    the leaf blade is simple (i.e., lobed or unlobed but not separated into leaflets)
    Leaves per node
    there are two leaves per node along the stem
    Specific leaf type
    the leaves are simple (i.e., lobed or unlobed but not separated into leaflets

  • 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 an odor, or it has an unpleasant or repellant odor

  • Stem, shoot, branch

    Aerial roots
    the plant has no aerial roots
    Bark texture
    • the bark of an adult plant is thin and smooth
    • the bark of an adult plant peels off easily or hangs off
    Branch brittleness (willows only)
    NA
    Branch cross-section
    the branch is circular in cross-section, or it has five or more sides, so that there are no sharp angles
    First-year cane (Rubus)
    NA
    Twig papillae (Vaccinium species only)
    NA
    Twig winter color
    • brown
    • orange
    Wings on branch
    the branch does not have wings on it
    armature on plant
    the plant does not have spines, prickles, or thorns

Wetland status

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

In New England

Distribution

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

Conservation status

Exact status definitions can vary from state to state. For details, please check with your state.

Massachusetts
not applicable (S-rank: SNA)

From Flora Novae Angliae dichotomous key

13.  Hypericum prolificum L. E

shrubby St. John’s-wort. Hypericum spathulatum (Spach) Steud. • CT, MA, ME, NH, RI, VT. Fields, forest edges, roadsides.

Native to North America?

Yes and no (some introduced)

Sometimes confused with

Hypericum densiflorum:
terminal cyme with 7 or more flowers, leaf blades mostly 3–7 mm wide, and capsules 1.5-3 mm wide (vs. H. prolificum, with the terminal cyme with mostly 3–7 flowers, leaf blades mostly 7–15 mm wide, and capsules 3-5 mm wide).
Hypericum frondosum:
inflorescence usually of solitary, terminal flowers, longer sepals 10–15 mm long, and petals 10–20 mm long (vs. H. prolificum, with the inflorescence a terminal cyme mostly 3-7 flowers, sepals 7 mm long or shorter, and 10 mm long or shorter).

Synonyms

  • Hypericum spathulatum (Spach) Steud.

Family

Hypericaceae

Genus

Hypericum