Thlaspi arvense
Common Name(s):
- Phonetic Spelling
- THLAS-pee ar-VEN-see
- Description
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Field Pennycress is an annual weed in the mustard family. It is native to Eurasia and is found in fields, along roadways and other disturbed areas. Its preference is for poor soils with some moisture in full sun but is tolerant of various conditions. It has a shallow root system and is easy to hand pull. It initially forms a rosette of leaves but these fade as the ribbed flower stem emerge. The flowers are tiny and white in elongated clusters with the flowers forming at the top and the fruits below. The distinctive seed pods are flat round papery pods with a top-notch that split to spill black seeds.
The mustard-garlic flavor of the leaves is not a favorite of grazing animals but the milk of dairy cows is affected if they eat it.
- See this plant in the following landscape:
- Cultivars / Varieties:
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- Tags:
- Cultivars / Varieties:
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- Tags:
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Attributes:
- Genus:
- Thlaspi
- Species:
- arvense
- Family:
- Brassicaceae
- Life Cycle:
- Annual
- Recommended Propagation Strategy:
- Seed
- Country Or Region Of Origin:
- Eurasia
- Distribution:
- Throughout N. America
- Wildlife Value:
- The nectar may attract small bees and flies. Some white butterflies and moths will lay their eggs on the leaves
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Whole Plant Traits:
- Plant Type:
- Annual
- Herb
- Weed
- Habit/Form:
- Erect
- Growth Rate:
- Rapid
- Maintenance:
- High
- Texture:
- Medium
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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:
- Clay
- Sand
- Shallow Rocky
- Soil pH:
- Acid (<6.0)
- Soil Drainage:
- Good Drainage
- Moist
- NC Region:
- Coastal
- Mountains
- Piedmont
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Fruit:
- Fruit Color:
- Brown/Copper
- Display/Harvest Time:
- Summer
- Fruit Type:
- Capsule
- Fruit Length:
- < 1 inch
- Fruit Width:
- < 1 inch
- Fruit Description:
- Fruit is a flat oval 2-parted pod about ½ inch long with a notch at the tip. It dries to a papery orange-tan shell. Each side of the pod holds up to 8 seeds that mature to nearly black.
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Flowers:
- Flower Color:
- White
- Flower Inflorescence:
- Raceme
- Flower Bloom Time:
- Spring
- Flower Petals:
- 4-5 petals/rays
- Flower Size:
- < 1 inch
- Flower Description:
- Elongating dense clusters of flowers form at the upper axils of leaves with small 1/8-1/4 inch white flowers opening at the top and fruit forming below. 4 white petals with 6 greenish-white anthers and a flat ovary. There are 4 green sepals with whitish edges below the petals.
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Leaves:
- Leaf Color:
- Green
- Leaf Type:
- Simple
- Leaf Arrangement:
- Alternate
- Rosulate
- Leaf Shape:
- Oblanceolate
- Oblong
- Leaf Margin:
- Dentate
- Undulate
- Hairs Present:
- No
- Leaf Length:
- 3-6 inches
- Leaf Width:
- 1-3 inches
- Leaf Description:
- Initially, a rosette of oblanceolate leaves is formed with a rounded tip, entire to wavy margins and short stems. These fade early as the flowering stem arises with oblong, stalkless and clasping leaves. The margins have rounded to pointed teeth.
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Stem:
- Stem Color:
- Green
- Stem Is Aromatic:
- No
- Stem Cross Section:
- Angular
- Stem Form:
- Straight
- Stem Description:
- Ribbed green stems may be branched at the top and may be winged
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Landscape:
- Landscape Location:
- Meadow
- Problems:
- Problem for Horses
- Weedy
