Understanding the Asiatic Dayflower
The Asiatic dayflower, scientifically known as Commelina communis, is a low-growing annual plant that is widespread across North America after being introduced from East Asia. It is often found in moist, disturbed areas like garden beds, roadsides, and fields. While many gardeners consider it a pesky weed due to its aggressive spreading nature, its distinctive flowers and foliage make it easily identifiable once you know what to look for.
Unlike the persistent rumors, the Asiatic dayflower is actually non-toxic and has a history of both edible and medicinal use. The edible parts include the leaves, flowers, and young shoots, which can be eaten raw or cooked. However, this plant's reputation has been unfairly linked with truly dangerous species due to its similar-sounding name.
Identification: What to Look For
To correctly identify the harmless Asiatic dayflower, keep an eye out for these key traits:
- Flowers: Each flower has two large, rounded, bright blue petals on top and a single, much smaller, inconspicuous white petal below, sometimes described as resembling 'Mickey Mouse ears'.
- Leaves: The lance-shaped leaves are alternate, have smooth margins, and feature parallel veins. A key feature is the membranous sheath at the base of the leaf that wraps around the stem.
- Stems: Stems are often prostrate at the base but grow upward at the tips, and they are typically smooth and hairless.
- Life Cycle: As its name suggests, individual flowers only last for a single day, blooming in the morning and closing in the afternoon.
The Critical Distinction: Dayflowers vs. Toxic Lilies
Confusion arises because the name 'dayflower' is often mixed up with 'daylily', and both are separate from 'true lilies.' This confusion is particularly dangerous for pet owners. While Asiatic dayflowers are benign, certain lily species are extremely toxic, especially to cats. Proper identification is the single most important step for ensuring safety.
| Feature | Asiatic Dayflower (Commelina communis) | True Lily (Lilium spp., e.g., Asiatic Lily) | Daylily (Hemerocallis spp.) |
|---|---|---|---|
| Toxicity | Non-toxic to humans and pets. | Highly toxic to cats; all parts are dangerous. Moderately toxic to dogs. | Highly toxic to cats; all parts are dangerous. Safe for dogs, but can cause mild stomach upset. |
| Flower Structure | Two large blue petals, one small white petal. | Large, trumpet-shaped flowers with six identical or near-identical petals. | Trumpet-shaped flowers with six identical petals, but only last for one day. |
| Leaf Structure | Lance-shaped leaves with parallel veins and a stem-clasping sheath at the base. | Leaves are arranged singly along the stem and do not have a prominent basal sheath. | Long, strap-like leaves that grow in clumps from the ground. |
| Root System | Fibrous, spreading roots that allow for aggressive growth. | Bulbous root system. | Fleshy root system, not a true bulb. |
Potential Considerations for Safety
While not poisonous, there are a few safety points to remember regarding the Asiatic dayflower and its relatives:
- Look-alikes: Be aware of other members of the spiderwort family, like Tradescantia pallida, which can cause contact dermatitis in some individuals and is generally considered toxic. If foraging, it is essential to be 100% certain of your identification.
- Environmental Contaminants: Since the plant has been shown to absorb heavy metals like copper, it is best to only harvest edible parts from areas known to have clean soil and away from roadsides where runoff and pollution are present.
- Invasiveness: For gardeners, its non-toxic nature doesn't eliminate its invasive tendency. Its ability to spread quickly means it can outcompete native plants. Managing its growth through pruning or removal is a common practice.
Edible and Medicinal Uses
Beyond its reputation as a weed, the Asiatic dayflower has a long history of use. The entire above-ground portion of the plant is considered edible, with the young leaves and shoots being particularly palatable. They have a mild flavor and a slightly mucilaginous texture, and can be added to salads or soups. The vibrant blue flowers make for a beautiful, colorful garnish on dishes.
In traditional medicine, the plant has been used for its diuretic, febrifuge (fever-reducing), and anti-inflammatory properties. A gargle made from the leaves was used to soothe tonsillitis, and a decoction of the dried plant was used to treat diarrhea and fever. Recent scientific studies have also confirmed the anti-inflammatory effects of extracts from Commelina communis. For more information on its traditional and medicinal uses, you can consult resources like the Plants For A Future database.
Conclusion: The Final Verdict on Poisonous Asiatic Dayflower
The verdict is clear: the Asiatic dayflower (Commelina communis) is not poisonous. The concern surrounding this plant stems from its misidentification with other toxic species, particularly true lilies and daylilies, which are dangerous for pets. While the dayflower is harmless and even edible, vigilance is required to correctly identify it, especially if you have pets or are considering foraging. By learning the distinct features of the Asiatic dayflower, you can confidently distinguish it from its toxic look-alikes and appreciate its harmless nature. It is a reminder that a plant's reputation can be undeserved and that knowledge of proper identification is essential for both gardening and pet safety.
Can my pet safely be around Asiatic dayflower, or should I be worried?
| Feature | Asiatic Dayflower | True Lily | Daylily |
|---|---|---|---|
| Pet Safety | Not known to be toxic to cats or dogs. | Extremely toxic to cats; all parts are dangerous. Moderately toxic to dogs. | Extremely toxic to cats; all parts are dangerous. Safe for dogs, but can cause mild stomach upset. |
| Ingestion Risk | Low-risk, non-toxic. | High-risk, life-threatening for cats. | High-risk, life-threatening for cats. |
| Symptoms if Ingested | Generally none, though minor digestive upset is possible if consumed in large quantities. | Vomiting, lethargy, loss of appetite, kidney failure (cats). | Vomiting, lethargy, loss of appetite, kidney failure (cats). |
Final Verdict
While many people worry that the Asiatic dayflower is a threat, the facts show it is a non-toxic, edible plant. The most significant danger associated with it is misidentification. By taking the time to learn its specific characteristics and understand the crucial differences from toxic lilies, you can ensure the safety of your family and pets. So, if you spot the distinctive blue, one-day blooms of the Asiatic dayflower, you can be sure that its bad reputation is simply a case of mistaken identity.
