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Trifolium dubium

Previously known as:

  • Trifolium minus var. microphyllum
Phonetic Spelling
try-FOH-lee-um DOO-bee-um
This plant is an invasive species in North Carolina
Description

Lesser Trefoil is an annual weed in the bean family found all over the world in disturbed sites, roadsides, meadows, and lawns.  It is a legume so it fixes nitrogen in the soil.  This plant is what is commonly used as the inspiration for the Irish Shamrock.  Tiny yellow flowers attract bees to their nectar from late spring to early fall.  It can be used for animal forage, it will often be seen in lawns where it handles foot traffic and mowing well.

Although this plant can cause issues with some plants, (see below), with others it can be beneficial.  When grown in an apple orchard the fruits produced can be tastier.  

The flowers grow in the form of a raceme and sit atop a long stalk.  Each raceme will contain 3 to 15 flowers 

Insects, Diseases, and Other Plant Problems:  This plant cannot grow in the shade.  It should not be planted near camellias or gooseberries.  It harbors a mite that may lead to fruit drop for the gooseberries and premature budding on your camellias.  

Considered to be invasive.

See this plant in the following landscape:
Cultivars / Varieties:
Tags:
#invasive#weeds#wildlife plant#weedy#legume#nectar plant#herbaceous#disturbed areas#larval host plant#herbaceous annual#nectar plant late spring#butterfly friendly#nectar plant early summer#nectar plant mid-summer#nectar plant late summer#nectar plant early fall#pollinator garden#bee friendly#roadside#meadows#forage#clouded sulphur butterfly
 
Cultivars / Varieties:
Tags:
#invasive#weeds#wildlife plant#weedy#legume#nectar plant#herbaceous#disturbed areas#larval host plant#herbaceous annual#nectar plant late spring#butterfly friendly#nectar plant early summer#nectar plant mid-summer#nectar plant late summer#nectar plant early fall#pollinator garden#bee friendly#roadside#meadows#forage#clouded sulphur butterfly
  • Attributes:
    Genus:
    Trifolium
    Species:
    dubium
    Family:
    Fabaceae
    Life Cycle:
    Annual
    Recommended Propagation Strategy:
    Division
    Seed
    Country Or Region Of Origin:
    Macronesia, Europe
    Wildlife Value:
    This plant supports Clouded Sulfur (Colias philodice) larvae which appear from May to October in the North and from March to November in the South. There are 3 flights in the North and 4 to 5 flights in the South. Adult Clouded Sulfur butterflies feed on flower nectar from many different plants. Flowers are pollinated by bees.
    Play Value:
    Attracts Pollinators
    Wildlife Larval Host
  • Whole Plant Traits:
    Plant Type:
    Annual
    Weed
    Woody Plant Leaf Characteristics:
    Deciduous
    Habit/Form:
    Ascending
    Growth Rate:
    Rapid
    Maintenance:
    Medium
    Texture:
    Medium
  • Cultural Conditions:
    Light:
    Full sun (6 or more hours of direct sunlight a day)
    Soil Texture:
    Clay
    Loam (Silt)
    Sand
    Soil pH:
    Acid (<6.0)
    Alkaline (>8.0)
    Neutral (6.0-8.0)
    Soil Drainage:
    Good Drainage
    Moist
    Available Space To Plant:
    12 inches-3 feet
    NC Region:
    Coastal
    USDA Plant Hardiness Zone:
    8a, 8b, 9b, 9a
  • Fruit:
    Fruit Type:
    Legume
    Fruit Length:
    < 1 inch
    Fruit Width:
    < 1 inch
    Fruit Description:
    Dry does not split open when ripe. Each contains 1 seed that will remain inside the calyx.
  • Flowers:
    Flower Color:
    Brown/Copper
    Gold/Yellow
    Flower Inflorescence:
    Head
    Raceme
    Flower Bloom Time:
    Fall
    Spring
    Summer
    Flower Petals:
    4-5 petals/rays
    Flower Size:
    < 1 inch
    Flower Description:
    Yellow flowers appear May-October and are self fertile as they have both male and female parts. As they age, they take on a yellowish-brown color. Each flower has 5 petals, while 3 to 15 flowers will bloom on the raceme.
  • Leaves:
    Woody Plant Leaf Characteristics:
    Deciduous
    Leaf Color:
    Green
    Leaf Type:
    Compound (Pinnately , Bipinnately, Palmately)
    Leaf Arrangement:
    Alternate
    Leaf Margin:
    Entire
    Serrate
    Hairs Present:
    No
    Leaf Length:
    < 1 inch
    Leaf Width:
    < 1 inch
    Leaf Description:
    2 to 3 leaflets with slightly curved margins.
  • Stem:
    Stem Is Aromatic:
    No
    Stem Surface:
    Hairy (pubescent)
    Stem Description:
    The then stem is limp or ascending with few hairs. It can lay along the ground or be erect.
  • Landscape:
    Landscape Location:
    Lawn
    Meadow
    Landscape Theme:
    Butterfly Garden
    Pollinator Garden
    Design Feature:
    Border
    Attracts:
    Bees
    Butterflies
    Pollinators
    Resistance To Challenges:
    Foot Traffic
    Poor Soil
    Problems:
    Invasive Species
    Weedy