Basic Information
Common Name: Tansy Mustard
Scientific Name: Descurainia pinnata
Native Habitat: North America
History / Discovery / Cultivator
Descurainia pinnata, commonly known as Tansy Mustard, boasts a history deeply intertwined with the landscapes of North America. It’s a plant that has quietly flourished, largely unnoticed by the grand narratives of botanical exploration and cultivation that often surround more flamboyant species. Its story is, instead, one of ecological adaptation and significance to indigenous peoples.
The formal botanical description and classification of Descurainia pinnata falls within the extensive work of the early botanists who cataloged the flora of the New World. These efforts, primarily occurring during the 18th and 19th centuries, were driven by a combination of scientific curiosity and the practical need to understand the resources available in newly explored territories. While a single individual “discoverer” might be difficult to pinpoint for such a widespread and relatively unassuming plant, the contributions of botanists who broadly surveyed the flora of North America are essential to understanding its history.
The plant’s significance lies not so much in intentional cultivation for ornamental or commercial purposes, but rather in its ecological role and traditional uses by Native American communities. Tansy Mustard is adaptable, thriving in a variety of habitats, from disturbed soils and roadsides to prairies and open woodlands. This adaptability has allowed it to colonize and persist across a wide geographical range, making it a familiar, if often overlooked, component of the North American landscape.
Evidence suggests that various Native American tribes utilized Descurainia pinnata for both food and medicinal purposes. The seeds, in particular, were a valuable resource. They were often ground into flour and used to make cakes or incorporated into other food preparations. The leaves, while sometimes bitter, could also be consumed, often cooked to reduce their pungency. Medicinally, different parts of the plant were employed to treat a range of ailments, though specific applications varied depending on the tribe and the availability of other resources.
Unlike some plants that were actively cultivated and bred to enhance particular traits, Tansy Mustard has largely remained in its wild form. There is little evidence to suggest significant selective breeding or cultivation efforts. Its value stemmed from its accessibility and abundance in its natural habitat, rather than any specialized agricultural practices. Its story represents a compelling example of a plant that has played a subtle, yet important, role in both the ecology and the cultural history of North America. Its continued presence serves as a reminder of the intricate connections between people, plants, and the landscapes they inhabit.
Plant Care Summary
| Category | General Requirement | Notes |
|---|---|---|
| Light | Full sun | Prefers at least 6 hours of direct sunlight daily. |
| Water | Low | Drought-tolerant; water sparingly, allowing soil to dry out. |
| Humidity | Low | Tolerant of dry air; does not require supplemental humidity. |
| Temp. Range | Moderate | Tolerates a wide range of temperatures; protect from severe frost. |
| Soil Type | Well-draining | Prefers sandy or gravelly soil with good drainage. Avoid heavy clay. |
| Fertilizer | Minimal | Generally does not require fertilization; avoid over-fertilizing. |
| Toxicity | Generally non-toxic | Considered safe for humans and pets, but may cause mild irritation. |
Botanical Insights
Adaptations
Descurainia pinnata exhibits several adaptations that contribute to its survival in its native environments. Its pinnately divided leaves, reminiscent of tansy, likely aid in reducing water loss through transpiration, an important adaptation for plants growing in drier habitats. The plant’s relatively small size and rapid growth cycle allow it to quickly capitalize on favorable conditions, such as after rainfall or disturbances. Additionally, its prolific seed production ensures the dispersal and propagation of the species across a wide area. The drought tolerance of Descurainia pinnata is also key to its success in arid regions of North America.
Propagation Methods
Tansy Mustard is primarily propagated by seed. Seeds can be directly sown in the garden in the fall or spring. For earlier starts, seeds can be sown indoors 6-8 weeks before the last expected frost. The plant readily self-seeds under favorable conditions. No special treatments are generally needed for seed germination.
Toxicology
While Descurainia pinnata is generally considered non-toxic, it’s important to note that it belongs to the mustard family (Brassicaceae). Some members of this family contain compounds that can cause mild irritation if ingested in large quantities. However, reports of significant toxicity are rare. Contact with the plant may cause mild skin irritation in sensitive individuals. As with any wild plant, caution is advised, and consumption should be avoided unless the plant is positively identified and known to be safe for consumption. If ingested, monitor for any signs of digestive upset and contact a medical professional or veterinarian if symptoms develop.
Common Problems
Pests:
- Aphids
- Flea beetles
- Cabbage white butterfly larvae
Diseases:
- Powdery mildew
- Root rot (in poorly drained soils)
Other:
- Bolting (premature flowering) – can occur in hot weather, making the leaves bitter.
- Yellowing leaves – can be caused by nutrient deficiencies or overwatering.
- Stunted growth – can be caused by poor soil or lack of sunlight.
Rarity & Value
Rarity:
Descurainia pinnata is not generally considered rare. It is a widespread and common plant across much of North America. However, local populations may be vulnerable to habitat loss due to development or agriculture. Certain unique or isolated varieties might be of interest to collectors, though this is not a widely sought-after plant.
Value:
The value of Descurainia pinnata is primarily ecological and historical, rather than monetary. As a native plant, it supports local ecosystems and provides food and habitat for wildlife. Its value to Native American cultures as a food and medicinal plant also contributes to its overall significance. You are unlikely to find this plant for sale in nurseries, and it has little commercial value.
