Erythronium americanum

A yellow trout lily produces an erect flower stalk with a nodding, bisexual flower with 6 recurved, yellow, lanceolate tepals. The 20 to 33 mm long tepals are composed of 3 petals and 3 petal-like sepals.[3] E. americanum does not flower for the first 4 to 7 years of its life.[5][6] In any given colony, only 0.5% will have flowers.[8][3]

Trout lilies bloom in early spring before the trees growing above them develop leaves. Blooming at this time allows them unobstructed access to sunlight and time to grow when soil nutrient levels are high. The flowers close at night.[8]

Non-flowering plants grow a single leaf whereas flowering plants grow 2 basal leaves.[9] The 8 to 23 centimeters long yellow trout lily leaves grow in the spring and range from elliptic to lanceolate leaves, the leaves may be mottled with gray to purple and have entire leaf margins.[3]

Erythronium americanum does not reproduce very effectively via sexual reproduction with only 10% of pollinated flowers developing seeds.[10] The fruit is a 12 to 15 mm long capsule that is held off the ground by the flower stalk.[3] E. americanum is a myrmecochorous plant, meaning that ants help disperse the seeds and reduce seed predation. To make the seeds more appealing to ants they have an elaiosome which is a structure that attracts ants.[11]

A trout lily grows from a 15 to 28 mm oval underground corm. The corm is often located in the upper 11 cm of soil although it may be as deep as 30 cm.[9][8] The corms of E. americanum are buried very deeply compared to other lily family plants. The corms are mostly composed of storage tissue containing large amounts of energy rich starch. The corm is covered by a papery husk which is the remains of the previous year's stalk.[12]

Trout lilies grow in colonies, some of which have been dated to be up to 300 years old.[2][4] The individuals within a colony will often reproduce asexually via a "dropper" or from small bulbs budding off of the main corm. A dropper is a tubular fleshy stem that grows out from a parent corm, up toward the surface and then penetrates deep into the soil where another corm is formed from the tip of the dropper. The stem connecting the daughter and parent corm then dies.[10]