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Clasping-leaved Venus' Looking-glass Triodanis perfoliata subsp. biflora

Previously known as:

  • Triodanis biflora
  • Triodanis perfoliata var. biflora
This plant is an invasive species in North Carolina
Description

Small Venus' looking-glass is a native annual in the Campanulaceae (bellflower) family.  Its common name is derived from an early botanical description of a similar appearing plant native to Europe. That was the Legousia speculum, which had seeds that were said to be as shiny as a looking glass.  The seeds of the Triodanis perfoliate subsp. biflora are too small to detect the shiny appearance. It is also said that the flattened seeds resemble a hand mirror, thus the common name.  

It is found all over the southern half of the U.S.A., Mexico and parts of South America most often in disturbed sites such as prairies, roadsides, rocky outcrops, gravel pits, open woods and grassy slopes. It prefers poor, dry, sandy or gravelly soil where there is not much competition with other plants.  

After blooming, it will fade away.  

Typical heights are up to 12", however, it can reach heights of up to 30".  Although the leaves are alternate, a pair of opposite leaves appear at the top of the stem. These leaves are somewhat larger than the lower leaves.  They are cordate and have wavy margins.  

The stems and leaves each have a milky sap.  

It has showy five petaled flowers that range in color from blue-violet to pink-purple to lavender.  The center holds a white style. The sepals, which form a cup for the flower, can have narrow triangular lobes that are shorter than the petals and form a tapered or sharp pointed tip.  The lower flowers are smaller than the upper flowers and do not open.  

Considered to be cleistogamous, whose lower, non-opening flowers are an automatic self pollinators.    

Small bees such as the Plasterer bee, Little Carpenter bee as well as bumblebees, flies, small butterflies and skippers frequent this plant. 

Insects, Diseases, and Other Plant Problems:  Can become invasive.  Deadheading can control its self-seeding.  

See this plant in the following landscape:
Cultivars / Varieties:
Tags:
#showy flowers#invasive#weeds#purple flowers#weedy#herbaceous#NC native#self-seeding#disturbed areas#hairy leaves#native wildflower#native annual#herbaceous annual#hairy stems#dry soils tolerant#butterfly friendly#bee friendly#native
 
Cultivars / Varieties:
Tags:
#showy flowers#invasive#weeds#purple flowers#weedy#herbaceous#NC native#self-seeding#disturbed areas#hairy leaves#native wildflower#native annual#herbaceous annual#hairy stems#dry soils tolerant#butterfly friendly#bee friendly#native
  • Attributes:
    Genus:
    Triodanis
    Species:
    perfoliata
    Family:
    Campanulaceae
    Life Cycle:
    Annual
    Recommended Propagation Strategy:
    Seed
    Country Or Region Of Origin:
    Southern USA from west coast to east, Mexico, South America
    Distribution:
    AL, AR, AZ, CA, FL, GA, HI, IL, KS, KY, LA, MO, MS, NC, NE, NM, NY, OK, OR, PA, SC, TN, TX, VA
    Wildlife Value:
    Small bees are attracted. The Plasterer Bee prefers the nectar.
    Play Value:
    Attractive Flowers
    Attracts Pollinators
    Wildlife Larval Host
  • Whole Plant Traits:
    Plant Type:
    Annual
    Herb
    Native Plant
    Weed
    Wildflower
    Habit/Form:
    Erect
    Growth Rate:
    Medium
    Maintenance:
    Medium
    Texture:
    Medium
  • Cultural Conditions:
    Light:
    Full sun (6 or more hours of direct sunlight a day)
    Partial Shade (Direct sunlight only part of the day, 2-6 hours)
    Soil Texture:
    Sand
    Shallow Rocky
    Soil pH:
    Neutral (6.0-8.0)
    Soil Drainage:
    Good Drainage
    Occasionally Dry
    Available Space To Plant:
    12 inches-3 feet
    NC Region:
    Coastal
    Mountains
    Piedmont
    USDA Plant Hardiness Zone:
    2a, 2b, 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b, 10a, 10b, 11a, 11b
  • Fruit:
    Fruit Color:
    Brown/Copper
    Fruit Type:
    Capsule
    Fruit Length:
    < 1 inch
    Fruit Width:
    < 1 inch
    Fruit Description:
    The fruits take the for of a 2-3 parted oval capsule with persistent calyx lobes spreading out at the tip. As they mature, they split from top to bottom, releasing many reddish-brown seeds.
  • Flowers:
    Flower Color:
    Pink
    Purple/Lavender
    Flower Inflorescence:
    Solitary
    Flower Value To Gardener:
    Showy
    Flower Bloom Time:
    Spring
    Summer
    Flower Shape:
    Bell
    Star
    Flower Petals:
    4-5 petals/rays
    Flower Size:
    < 1 inch
    Flower Description:
    5-petaled purple-violet to pink solitary flowers with center disc flowers. They are bell or star shape on upper stems. Flowers on the lowest part of the stem are small, self-fertile, without petals and do not open. The upper flowers are showy.
  • Leaves:
    Leaf Color:
    Green
    Leaf Type:
    Simple
    Leaf Arrangement:
    Alternate
    Leaf Shape:
    Cordate
    Ovate
    Reniform
    Leaf Margin:
    Entire
    Serrate
    Hairs Present:
    Yes
    Leaf Length:
    < 1 inch
    Leaf Width:
    < 1 inch
    Leaf Description:
    Alternate, simple, sessile, light green leaves are broadly egg-shaped to heart or kidney-shaped, rounded to somewhat pointed at the tip. Margins are serrate to entire. They are up to 1 inch long and nearly as wide. The leaves are stalkless and clasp the stem at the base. Stiff hairs may cover the surface except for the upper leaves, which may be hairless.
  • Stem:
    Stem Color:
    Green
    Stem Is Aromatic:
    No
    Stem Cross Section:
    Angular
    Stem Form:
    Straight
    Stem Surface:
    Hairy (pubescent)
    Stem Description:
    The light green, single, erect stems are angled, stiffly hairy (white) along the angles, unbranched or branched near the base. They tend to be weak.
  • Landscape:
    Landscape Theme:
    Native Garden
    Pollinator Garden
    Attracts:
    Bees
    Butterflies
    Pollinators
    Problems:
    Invasive Species