If the flower is successfully pollinated, the petals wither, leaving behind a fruit that ripens to a dark red berry-like capsule, 1 to 1.5 centimeters long.

[22] In 1803 André Michaux introduced the name Trillium rhomboideum to describe a form of T. erectum with black fruit in "the high mountains of North Carolina".

A decade later in 1813, Frederick Traugott Pursh referred to Michaux's variety more simply as Trillium erectum var. atropurpureum.

[25][26] The epithet atropurpureum means "dark-purple coloured",[27] a reference to the petal color of certain forms of T. erectum.

[30][24] The word album means "bright, dead-white",[31] a reference to the variety's white petals, a distinctive feature noted by both Michaux and Pursh.

[32] In his description, he added long anthers to the list of characters cited by Michaux while expanding the range of the taxon to include North Carolina, Tennessee, and Georgia.

Gates recognized the existence of two distinct forms of T. erectum with white petals, one of which was represented by the previously mentioned Trillium album (Michx.)

POWO cites the Flora of North America (FNA) as an authority for Trillium erectum var.

[3] The treatment of the variety in FNA expands the original concept described by Michaux to include the occasional white-flowered red trillium found throughout the range of the species.

[37] Under this scheme, all non-white petal colors (including yellow) comprise the typical variety (var. erectum).

Noting that its distribution is poorly understood, Flora of the Southeastern United States (FSUS) describes a white-flowered variety of T. erectum common to the foothills of the Great Smoky Mountains, in North Carolina and Tennessee, but rare elsewhere.

Its range extends from northern Georgia in the southeastern United States to Quebec and New Brunswick in eastern Canada, and as far west as Michigan and southern Ontario.

album (as described in the Flora of the Southeastern United States) occurs in western North Carolina, eastern Tennessee, and other areas surrounding the Great Smoky Mountains, primarily at elevations less than 450 m (1,480 ft).

It produces fetid or putrid odors purported to attract carrion fly and beetle pollinators.

[citation needed] The root of the red trillium was used by various indigenous peoples of North America as an aid in childbirth, hence the common name birthwort or birthroot (which is sometimes corrupted to bethroot).