Plant Profile: Tricyrtis formosana

The Toad Lily, also known as the Formosan Toad Lily, is a striking perennial from the lily family that thrives in shady environments and features small, orchid-like blooms. The genus name "Tricyrtis" derives from Greek, where "tri" signifies three and "kyrtos" refers to a swelling or bulging shape. This nomenclature highlights the three sac-like nectaries located at the base of the tepals, which consist of three inner petals and three outer sepals. The species name "formosana" indicates its origin in Formosa, the historical name for present-day Taiwan.

The term "Toad Lily" is inspired by the flower's spotted appearance, reminiscent of toads, along with the warty, sac-like bumps that represent the nectaries. The Tricyrtis genus is indigenous to regions including China, Korea, Japan, Nepal, Taiwan, and the Philippines. These flowers typically grow at the edges of forests, near creek beds, and along roadways. While the Tricyrtis genus encompasses around 20 species, only Tricyrtis formosana and Tricyrtis hirta are commonly found in gardens, with the Toad Lily being native to Taiwan.

This plant features an upright stem that can reach heights of up to 40 inches, adorned with glossy leaves. Clusters of small flowers, which are white with reddish-purple speckles, bloom at the stem's tip. Notably, the flowers of this species are smaller compared to many others. The Toad Lily propagates through underground rhizomes and can also be grown from seeds, stem cuttings, or divisions. Seeds should be harvested in late fall when the capsules open, and they must be sown fresh without being buried in soil. Some species may require cold stratification for germination. Divisions should be performed in spring, ensuring that each piece includes an underground growth bud for successful establishment. Stem cuttings root easily during the summer months.

The Toad Lily prefers light, open shade and does not thrive in deep shade; exposure to full sun can scorch its leaves. Prolonged exposure to temperatures below 28 degrees Fahrenheit can severely damage the plant.

In recent years, Toad Lilies have made their way into gardens across the United States, gaining popularity in ornamental settings since the mid-1990s. They are resistant to deer, though slugs and snails may occasionally pose a threat. Rabbits are known to nibble on new growth. The Tricyrtis floral virus, transmitted by aphids, can cause the flower's color to become mottled before turning entirely purple. Additionally, anthracnose, a fungal disease, can lead to orange spots on the stems and leaves, which can be mitigated by keeping the foliage dry and watering only at the plant's base.

To fully appreciate Toad Lilies, they are best viewed up close, such as along borders or pathways. They enhance shade gardens when paired with plants like hostas, ferns, and astilbe, and they also serve well as cut flowers. Various cultivars exhibit variegated foliage, and some showcase purple flowers adorned with dark spots.

Alternative native plants that complement the Toad Lily include Mimulus ringens, Viola canadensis, Clinopodium nepeta, and Verbena.

In terms of pests and diseases, slugs and snails may be attracted to the Toad Lily, while Tricyrtis floral virus and anthracnose are common ailments affecting the plant.