Weed Information: Mimulus guttatus (monkeyflower, common large)
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Mimulus guttatus (monkeyflower, common large)

Family: Scrophulariaceae

Description

Very common along drainage ditches, bogs, seeps, springs, etc. Often with water speedwell, watercress, and duckweed. The lower leaves are long stemmed while the upper leaves are sessile and clasping.

Characteristics

Flower Color
  • Red (or pink)
  • Red-orange
  • Orange
  • Yellow-orange
  • Yellow
  • Red-purple
  • Multi-colored
Inflorescence Type (How the flowers are arranged on the plant)
  • Terminal raceme
Number of Petals
  • 5 petals
Petal Separation
  • United from 25% - 75% length
Petal Tip
  • Rounded
Flower Symmetry
  • Flowers strongly irregular
Flower Length (Head length in the Asteraceae)
  • 1.5 cm (.6 inch)
  • 2.0 cm (.8 inch)
  • 2.5 cm (1.0 inch)
  • 3.0 cm (1.2 inches)
  • 3.5 cm (1.4 inches)
  • 4.0 cm (1.6 inches)
Flower Width (Head width in the Asteraceae)
  • 8 mm (.32 inch)
  • 9 mm (.36 inch)
  • 1.0 cm (.40 inch)
  • 1.5 cm (.60 inch)
  • 2.0 cm (.80 inch)
  • 2.5 cm (1.0 inch)
  • 3.0 cm (1.2 inches)
Number of Sepals
  • 5 sepals
Sepal Separation
  • United > 75% of length
Sepal Tip
  • Pointed
Flower Sex
  • Bisexual (perfect)
Number of Styles
  • 1 style
Number of Stamens
  • 4 stamens
Stamens Attached to the Petals
  • Stamens attached to the petals
Stamens Connate (united)
  • Filaments or anthers NOT united

Carpel Separation
  • Carpels united (or one)
Number of Carpels
  • 2 carpels
Ovary Position
  • Superior (hypogynous)
Fruit Type
  • Capsule, 2-celled
Fruit Length at Maturity
  • 7 mm (.28 inch)
  • 8 mm (.32 inch)
  • 9 mm (.36 inch)
  • 1.0 cm (.40 inch)
Fruit Width at Maturity
  • 3 mm (.12 inch)
  • 4 mm (.16 inch)
  • 5 mm (.20 inch)
Burs
  • Fruit or seed NOT bur-like

Leaf Arrangement
  • Opposite
Leaf Type
  • Simple (including lobed leaves)
Stipules
  • Lacking
Tendrils
  • Tendrils absent
Venation
  • Arcuate
  • Palmate
Petiole (leaf stem) Blade Ratio
  • Petiole absent (leaf sessile)
  • Petiole < 25% total length
  • Petiole 25% - 75% total length
  • Petiole > 75% total length
Leaf Length (blade PLUS petiole)
  • 1 - 2 cm (.40 - .80 inch)
  • 2 - 4 cm (.80 - 1.60 inches)
  • 4 - 10 cm (1.60 - 4.0 inches)
  • 1 - 2 dm (4.0 - 8.0 inches)
Leaf Width
  • 2 - 4 cm (.80 - 1.6 inches)
  • 4 - 10 cm (1.6 - 4.0 inches)
Leaf Shape (simple leaves only)
  • Deltoid (triangular)
  • Orbicular (round)
  • Oval
Leaf or Leaflet Margin
  • Dentate
  • Entire
Succulence
  • Succulent
  • Not succulent
Leaf or Leaflet Blade Base
  • Acute (cuneate)
  • Clasping
  • Rounded
Leaf or Leaflet Tip
  • Rounded (obtuse)
Leaf or Leaflet Blade Surface
  • Glabrous (NO hairs)
  • Glandular
  • Pubescent

Milky Juice
  • Juice NOT milky (watery)
Woodiness
  • Herbaceous
Spines or Thorns
  • Spines or Thorns ABSENT
Aromatic (vegetative structures)
  • Not aromatic
Life Cycle
  • Perennial
Growth Habit (while flowering)
  • Spreading ascending
  • Erect, spherical (bushy)
Plant Height at Maturity
  • 5 - 10 cm (2.0 - 4.0 inches)
  • 1 - 2 dm (4.0 - 8.0 inches)
  • 2 - 4 dm (8.0 - 16.0 inches)
  • 4 - 6 dm (1.3 - 2.0 feet)
  • 6 - 8 dm (2.0 - 2.6 feet)
  • 8 - 10 dm (2.6 - 3.3 feet)
Wind Dissemination
  • Not wind disseminated
Moisture Regime
  • Aquatic
  • Semi-aquatic
  • Seasonally saturated
Chlorophyll
  • Present

Stem Cross Section
  • Ridged
  • Round
Flowering Stem Leaves
  • Stem leaves greatly reduced
  • Stem uniformly leafy
Main Stem Branches
  • Main stem unbranched
  • Main stem branched

Root or Vegetative Propagule
  • Fibrous

US State
  • Connecticut
  • Delaware
  • Michigan
  • New York
  • Pennsylvania
  • Texas
  • Alaska
  • Arizona
  • California
  • Colorado
  • Idaho
  • Montana
  • North Dakota
  • New Mexico
  • Nevada
  • Oregon
  • South Dakota
  • Utah
  • Washington
  • Wyoming
  • Nebraska
Canadian Province or Territory
  • British Columbia
  • New Brunswick
  • Alberta
  • Newfoundland
  • Saskatchewan
  • Yukon
  • Northwest Territory

  • California Growers Weed Identification Handbook, 1968 - 1998 University of California Publication # 4030-1, See page: 141
  • Weeds of California, 1970, State of California Publications and Documents. See page: 398, 399
  • Listed as a `Weed` by the Biota of North America Program, 2008 x
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