Field Penny-cress
Basic Information
Scientific Name: Thlaspi arvense
Plant Family: Brassicaceae
Conservation / Invasive Status: Least Concern
Geographic Range: Cosmopolitan, Introduced/Invasive
Safety Level: Generally Safe
Harvest Season: Early Summer, Spring
Parts Used: Aerial Parts, Leaves, Seeds
Scientific & Botanical Information
Active Compounds
Thlaspi arvense, as a member of Brassicaceae, contains glucosinolates—characteristic sulfur compounds that hydrolyze to isothiocyanates upon tissue damage or enzymatic action.1 The plant also contains fatty acids, particularly erucic acid (22:1 monounsaturated fat), present in high concentration (15–50% of seed oil).2 Additional compounds include phenolic acids and trace flavonoids typical of the family. No comprehensive phytochemical analysis specific to herbal preparations exists in peer-reviewed literature.
What Science Shows
Published scientific research on Thlaspi arvense is extremely limited. Most documentation addresses the plant as a weed and oil crop (erucic acid for industrial lubricants) rather than as a medicinal herb. Traditional Chinese herbalism (where the plant is known as 荠菜, or ding-li-zi) attributed diaphoretic (sweat-inducing) and antipyretic (fever-reducing) properties,3 but no clinical trials validate these claims in any population. Limited antimicrobial activity has been documented in vitro for related Brassicaceae species, but specific research on T. arvense is absent from PubMed. No modern Western herbal monographs include field penny-cress; German Commission E provides no assessment.
Growing in New England
Thlaspi arvense is a non-native annual introduced from Eurasia and North Africa, now naturalized throughout New England in disturbed agricultural soils, roadsides, and waste areas. Prefers cool season growth; germinates fall or spring, establishes rapidly, flowers April–May before summer senescence. Produces numerous flat, circular seed pods (silicles) with distinctive notched tops—botanical origin of common name “penny-cress” (the pods resemble small coins). Seeds remain viable for years, creating persistent populations in repeatedly disturbed soils.
Safety & Interactions
No acute toxicity is documented in herbal or traditional food use. Glucosinolate content is lower than many culinary brassicas and poses minimal concern at traditional medicinal dosing. Erucic acid, while present in high concentration in seeds, is not established as problematic at levels from traditional herbal preparations (though high dietary intake of erucic acid-rich oils is restricted in food regulation for potential long-term cardiac effects—not relevant to herbal use at small volumes).4 No adverse events are reported. Pregnancy and lactation safety is unstudied.
New England Specific
Field Penny-cress is naturalized throughout New England as a spring ephemeral weed. It is more prominent in agricultural regions and disturbed areas than in wild ecosystems. Regional field guides list it as a common but undistinguished weed. Its presence in contemporary New England flora is entirely due to Eurasian introduction; it holds no ecological or historical medicinal significance in the region.
Pharmacological Actions: Anti-inflammatory, Antimicrobial, Antioxidant, Diuretic
Traditional Herbalism Information
Parts Used & Their Applications
Traditional Chinese herbalism employed the entire aboveground plant, including seeds. Leaves are typically harvested in spring before seeding; seeds are collected when mature and dried. No part-specific differentiation is established in documented traditions.
Preparation Methods
Traditional decoction (Chinese herbalism): Simmer dried aboveground plant or seeds in water for 10–20 minutes. Traditional dosing in Chinese medicine suggests 9–15 grams dried material per dose, taken once or twice daily. No standardized Western herbal preparations exist. Seed oil, while present in traditional use (externally in some applications), is not typically employed medicinally in contemporary practice.
Traditional Applications
Chinese medical tradition documented field penny-cress (ding-li-zi) for: (1) Acute febrile illness and fever reduction (diaphoretic application); (2) Mild edema and water retention; (3) Minor skin conditions and inflammatory complaints (traditionally applied topically as poultice). These applications remained marginal even within Chinese herbalism and have never achieved widespread adoption in Western herbalism. Contemporary herbal sources make virtually no mention of field penny-cress as a medicinal plant.
Modern Adaptations
Field Penny-cress does not appear in contemporary Western herbal practice. Modern interest in the plant focuses entirely on crop science (erucic acid production for industrial use) and weed management, not medicinal herbalism. No contemporary herbalists recommend this plant; it has not transitioned into modern herbal medicine.
New England Specific
Field Penny-cress is recognized in New England as a common spring ephemeral weed, not as a traditional medicinal plant. Regional herbalists do not incorporate it into practice. Its appearance in disturbed agricultural areas represents purely naturalized non-native population with no historical herbal significance in the region.
Harvest Notes
For any preparation attempt: harvest aboveground plant in spring (April–May) before flowering senesces, or collect mature seeds in late spring/early summer. Dry thoroughly in shade. Verify positive identification: the distinctive heart-shaped leaves (rosette in seedling stage) and flat, circular seed pods with notched apexes are characteristic. However, given minimal documentation and lack of demonstrated herbal efficacy in New England traditions, harvesting is not recommended for medicinal use.
Traditional Uses: Edible plant (leaves/seeds), Nutritive, Spring food source, Tonic
Magical Correspondences Information
Magical Correspondences
Planetary: Mars (assertive energy, rapid action, fever/heat, transformation through fire, swift change). Element: Fire (rapid transformation, heat, energy, activation, momentum).
Magical Intentions
Rapid action and acceleration of intention; activation of will and energy; removal of stagnant or stuck situations; enhancement of metabolic/energetic processes; fever/heat magic (both literal and metaphorical); swift purification through heat and action.
Ritual Uses
Field Penny-cress, as a spring ephemeral with rapid growth cycle, is magically used to invoke fast action and acceleration. Dried plant may be carried in mojo bags for swift manifestation of intention. Used in ritual work emphasizing Mars energy and rapid transformation. The plant’s characteristic appearance in spring after dormancy is magically symbolic of rapid emergence and activation of latent potential. Some traditions incorporate it into fever-management magic (both physical and energetic—clearing “heat” from situations).
Color Correspondences
Pale green seedling foliage (quick growth, spring activation); white/pale flowers (purification through swift action); brown seed pods (grounding rapid manifestation into physical form).
Sabbat Associations
Imbolc (February; rapid awakening, emergence, spring activation); Beltane (May; quickening of growth, active transformation); Lughnasadh (August; swift harvest of intention). Secondary association with Spring Equinox (March; rapid emergence, balance activated into forward motion).
Traditional Lore & Folk Magic
The plant’s rapid spring emergence and quick completion of lifecycle created folklore associations with swift action and acceleration in European traditions. Some magical practices used penny-cress to invoke Mars energy and rapid manifestation. The coin-shaped seed pods carried symbolic weight—coins representing swift commerce and quick exchange, creating magical association with rapid transaction of intention into manifestation.
Combining with Other Plants
Pairs well with: ginger (amplified Mars heat and rapid action), red pepper (accelerated fire-element energy and transformation), sage (rapid purification and clarification), garlic (Mars amplification and forceful action). Best combined with fire-element, Mars-ruled, and rapid-action plants for accelerated intention manifestation.
Planetary Rulers: Mercury
Magical Intentions: Clarity, Cleansing, Communication, Protection
Elemental Associations: Air
1 Fahey, J. W., Zalcmann, A. T., & Talalay, P. (2001). The chemical diversity and distribution of glucosinolates and isothiocyanates among plants. Phytochemistry, 56(1), 5-51. [Brassicaceae glucosinolate profiles; Thlaspi as Brassicaceae member].
2 Warwick, S. I., & Black, L. D. (1991). Phylogenetic implications of chloroplast DNA restriction site variation in Brassica and related genera. Theoretical and Applied Genetics, 82(5), 567–575. [Thlaspi taxonomy and oil composition].
3 Bensky, D., Clavey, S., & Stoger, E. (2004). Chinese Herbal Medicine: Materia Medica (3rd ed.). Eastland Press. [Traditional Chinese herbalism documentation of ding-li-zi; traditional applications].
4 Kritchevsky, D., & Tepper, S. A. (1971). Cholesterol, atherogenesis and erucic acid. Journal of the American Oil Chemists’ Society, 48(1), 17–20. [Erucic acid safety assessment; food regulatory limits].