Plant of the Week
Relict Trillium (Trillium reliquum)
By Mark Pistrang
All trillium species belong to the Liliaceae (lily) family and are rhizomatous herbs with unbranched stems. Trillium plants produce no true leaves or stems above ground. The “stem” is actually just an extension of the horizontal rhizome and produces tiny, scalelike leaves (cataphylls). The aboveground plant is technically a flowering scape, and the leaf-like structures are actually bracts subtending the flower. Despite their morphological origins, the bracts have external and internal structure similar to that of a leaf, function in photosynthesis, and most authors refer to them as leaves.
Trilliums are generally divided into two major groups, the pedicellate and sessile trilliums. In the pedicillate trilliums, the flower sits upon a pedicel that extends from the whorl of bracts, “erect” above the bracts or “nodding” recurved under the bracts. In the sessile trilliums, there is no pedicel and the flower appears to arise directly from the bracts.
Known from only a few locations in Georgia, South Carolina, and Alabama, relict trillium was listed endangered by the US Fish and Wildlife Service in 1988. This sessile trillium blooms from early March through April and occurs in rich, mixed-deciduous forests on slopes, bluffs, stream-flats, and floodplains. This species is of high conservation concern and all sites should be protected. Take only pictures; let’s not let this trillium become a relict!
For More Information
- PLANTS Profile - Trillium reliquum, relict trillium
- Flora of North America: Trillium reliquum
- Celebrating Wildflowers: Threatened, Endangered, and Proposed (TEP) Plant Profile: Trillium reliquum, relict trillium
- Case, F.W., R.B. Case. 1997. Trilliums. Timber Press, Portland, OR.