Toadshade

Description

Trillium sessile is a species of flowering plant in the bunchflower family Melanthiaceae. The specific epithet sessile means "attached without a distinct stalk", an apparent reference to its stalkless flower. It is commonly known as toadshade (not to be confused with Trillium recurvatum, which is also known by that name) or toad trillium. It is also called sessile trillium or sessile-flowered wake-robin, however it is not the only member of the genus with a sessile flower. Trillium sessile is endemic to the eastern half of the United States. It has the widest range of any species of sessile-flowered Trillium. There are two subpopulations geographically separated by a large gap in central Illinois where the species is strangely absent. Trillium sessile was one of three Trillium species described by the Swedish botanist Carl Linnaeus in 1753. It is a small perennial, herbaceous plant with three leaves, but unlike other sessile-flowered trilliums, the leaves are often not mottled. It has a single trimerous flower with three reddish-purple petals and six distinctive stamens that aid identification. Trillium sessile is a perennial, clump-forming herbaceous plant with a thick underground rhizome. Like all trilliums, it has a whorl of three bracts (leaves) and a single trimerous flower with 3 sepals, 3 petals, two whorls of 3 stamens each, and 3 carpels (fused into a single ovary with 3 stigmas). A single plant has one or two erect scapes (stems) per rhizome, each scape up to 25 cm (9.8 in) tall. The sessile (stalkless) bracts are elliptic, up to 10 cm (3.9 in) long and 8 cm (3.1 in) wide. The bracts may or may not be mottled. The erect, sessile flower nestled in the middle of the three bracts has a spicy, pungent odor. The sepals are mostly green but often streaked with purple along the edges or at the base of each sepal. The average length and width of a sepal is 21 mm (0.8 in) and 5.7 mm (0.2 in), respectively. The petals are erect and long-lasting. Although their shape and color are variable, a typical plant will have elliptic, reddish-purple petals. The base of a petal is narrowed and, in some cases, will have a very short claw-like base about 2 mm (0.1 in) long.