Basic Information
Common Name: Caucasian Penny-cress
Scientific Name: Pachyphragma macrophyllum
Native Habitat: Shaded woodlands of the Caucasus and surrounding regions.
History / Discovery / Cultivator
Pachyphragma macrophyllum, commonly known as Caucasian Penny-cress, hails from the shady, moist woodlands of the Caucasus region, encompassing areas such as Georgia, Armenia, Azerbaijan, and parts of Russia and Turkey. The plant’s scientific name reflects its notable features: “Pachyphragma” derives from Greek, referring to the thickened septum (partition) within the seed pod, while “macrophyllum” signifies “large-leaved,” a characteristic readily observed in its foliage.
While the precise date of its formal botanical discovery remains somewhat obscure in readily available literature, plants from the Caucasus have been of interest to botanists since at least the 18th century, when expeditions explored the region’s rich flora. It is likely that Pachyphragma macrophyllum was documented and classified during one of these botanical surveys, contributing to its inclusion in scientific catalogues and herbaria.
The cultivation of Caucasian Penny-cress, however, is a more recent phenomenon, largely driven by its appeal as a groundcover in shade gardens and woodland settings. Gardeners appreciate its evergreen foliage, delicate white flowers, and ability to thrive in challenging conditions where other plants struggle. The plant’s suitability for these environments makes it a valuable addition to landscaping schemes seeking to create naturalistic, low-maintenance spaces.
No single individual can be pinpointed as the primary “cultivator” or popularizer of Caucasian Penny-cress. Its increased use in horticulture is more attributable to the collective efforts of nurseries and garden enthusiasts who recognized its potential and propagated it for wider distribution. Botanical gardens, particularly those with a focus on Eurasian flora, also played a role in showcasing the plant’s beauty and adaptability.
The plant’s introduction and subsequent adoption in gardens outside of its native range reflect a broader trend of utilizing plants from around the world to enhance landscapes and diversify horticultural offerings. Caucasian Penny-cress has proven to be a resilient and adaptable species, capable of flourishing in a variety of climates and soil types, further contributing to its popularity among gardeners seeking easy-to-grow groundcovers. As awareness of sustainable gardening practices grows, the plant’s low-maintenance nature and ability to suppress weeds further solidify its appeal, making it a valuable asset in creating environmentally friendly and visually appealing landscapes.
Plant Care Summary
| Category | General Requirement | Notes |
|---|---|---|
| Light | Partial to Full Shade | Prefers shade, tolerates some morning sun. Avoid harsh afternoon sun. |
| Water | Moderate | Keep soil consistently moist, especially during dry periods. |
| Humidity | Moderate | Generally tolerant of average humidity levels. |
| Temp. Range | Moderate | Hardy to zones 5-8. |
| Soil Type | Well-draining, Humus-rich | Prefers moist, fertile soil with plenty of organic matter. |
| Fertilizer | Light | Apply a balanced fertilizer in spring. |
| Toxicity | Non-toxic | Generally considered non-toxic to humans and pets. |
Botanical Insights
Adaptations
Caucasian Penny-cress exhibits several key adaptations that contribute to its success in its native woodland environment. Its broad, evergreen leaves are well-suited for capturing diffused sunlight that penetrates the canopy. The leaves’ perennial nature allows the plant to maximize photosynthesis throughout the year, even during milder winter months. Its preference for moist, humus-rich soil reflects its adaptation to the shaded, damp conditions of woodland floors, where decaying organic matter provides essential nutrients. The plant’s creeping growth habit allows it to spread effectively as a groundcover, suppressing weeds and colonizing available space. Finally, its tolerance of shade and relatively low light requirements allow it to thrive in areas where other flowering plants struggle to survive.
Propagation Methods
Several methods can be used to propagate Caucasian Penny-cress. Division is a reliable method, especially in the spring or fall, where established clumps can be carefully separated and replanted. Stem cuttings can also be taken in the spring or early summer; these should be rooted in a well-draining medium under high humidity. Seed propagation is possible but can be slow and may require a period of cold stratification to break dormancy. Self-seeding may occur in ideal conditions.
Toxicology
Caucasian Penny-cress is generally considered non-toxic to humans and pets. While ingestion may cause mild gastrointestinal upset in some individuals, serious reactions are extremely rare. The ASPCA (American Society for the Prevention of Cruelty to Animals) does not list this plant as toxic to dogs, cats, or horses. However, it’s always a good practice to prevent pets or children from consuming any plant material in large quantities.
Common Problems
Pests:
- Slugs
- Snails
- Aphids
Diseases:
- Powdery Mildew
- Root rot (in poorly drained soils)
Other:
- Leaf scorch: Caused by excessive sun exposure.
- Stunted growth: Caused by nutrient deficiency or overly dry conditions.
- Yellowing leaves: May be caused by overwatering or poor drainage.
Rarity & Value
Rarity:
Caucasian Penny-cress is not generally considered rare in cultivation, particularly in regions with suitable climates. However, specific variegated forms or cultivars with unique characteristics might be less common and therefore considered more desirable by collectors. Limited availability in certain nurseries or geographic areas can also contribute to perceived rarity.
Value:
The value of Caucasian Penny-cress is generally modest. Mature, well-established plants in larger containers command higher prices. Variegated cultivars or specimens with unique foliage patterns are typically more valuable than standard green forms. The overall health and vigor of the plant, along with its presentation (e.g., clean, pest-free foliage), also influence its market value. Collector interest and current trends in groundcover plants also play a role in determining the plant’s perceived worth.
