Relict Trillium

Description:

Relict trillium is one of the first trillium species in Georgia and South Carolina to appear in the early spring (NatureServe 2003). Relict trillium is a perennial herb with 3 mottled leaves at the top of an S-shaped, somewhat decumbent stem, approximately 5 to 25 cm in length, often with the leaf whorl resting on the leaf litter (Patrick et. al. 1995 and USFWS 1991). A sessile, 3-petaled flower appears at the apex of the stem in early spring. The leaves of relict trillium are elliptic to orbicular, 5 to 14 cm in length and almost as wide. The leaves narrow to a pointed apex where the margins are nearly straight, thus the apex is sharply pointed and evenly tapered (acute). The leaves have five shades of color ranging from green through blue-green to silver, with a strong, central, silvery stripe on the upper, center leaf surface. The flowers of relict trillium are 22 to 60 mm in length and are less than half as long as the leaves (Patrick, et. al. 1995). The flowers range in color from greenish to brownish-purple and, occasionally, to pure yellow (NatureServe 2003). It has three sepals that are loosely spreading, usually with purplish on the inner sepal surface. The three petals are more erect, slightly twisted, and range in color from dark purple to yellow. The stamens are about half as long as the petals, and the tip of the anther is prolonged into a distinct beak (Patrick et. al. 1995). Like other trillium plants, this species dies back to its tuberous rhizome after the fruit matures (USFWS 1991). From May to early June, relict trillium produces an ovid to globose fleshy capsule (fruit) which is 1.0 to 1.5 cm in diameter. The capsule contains approximately 10 to 45 plump seeds. Surveys for the species must be conducted during its flowering period as its flower features are needed for a positive identification (Patrick et. al. 1995).

Relict trillium is distinguished from trailing trillium (Trillium decumbens), the only other trillium species having decumbent stems, by its glabrous rather than puberulent scapes. Also, the anther sacs are introrse in the former species, extrorse in the latter. Bracts of both longbract wakerobin (T. underwoodii) and Chattahoochee River wakerobin (Trillium decipiens) resemble those of relict trillium in their mottled leave pattern. All species exhibit multiple shades of green and a pale mid-rib stripe. The bract shape in relict trillium, however, is elliptic with a convex outline from the middle to the apex. In the other two species, the bract shape is narrowly ovate with straight sides from the middle to the sharply acute apex. Curved, more or less decumbent stems vs. straight, erect stems also aid in distinguishing relict from the other two more widespread similar-appearing species in the Southeast (NatureServe 2003). The photographs were taken at one of the larger relict trillium populations in South Carolina near Augusta, Georgia.

Habitat:

Relict trillium prefers mature, moist, undisturbed hardwood forests with an understory free of thick shrubs and vines. The soils on which this plant occurs range from alluvial sands to rocky clays, but they all have a high organic content in their upper layer. The forests can be on slopes of various aspects and inclinations or on bottomlands and floodplains. (USFWS 1991).

Range:

Relict trillium inhabits the Coastal Plain of southeastern Alabama and adjacent southwestern Georgia. The species is found near the Fall Line on both the Coastal Plain and the Piedmont Plateau in west-central Georgia. Relict trillium is disjunct just above the Fall Line along the Savannah River in Georgia and adjacent South Carolina (Patrick et. al. 1995). Approximately 25 relict trillium populations are currently known to exist in limited portions of Alabama, Georgia, and South Carolina. Most of these populations are in areas suitable for, or directly threatened by, development. The largest and most vigorous populations are in the Lower Piedmont/Fall Line Hills Province, in drainages of both the Savannah and Chattahoochee Rivers (NatureServe 2003). A total of 21 plant populations exist in Alabama (four populations); Georgia (14 populations); and South Carolina (3 populations). Population numbers range from 20 to several thousand plants, but at least 10 of these populations support less than 200 plants. Alabama's populations are located in Henry, Lee, and Bullock counties. South Carolina has populations In Aiken and Edgefield Counties. Georgia's populations are found in Clay, Lee, Macon, Early, Talbot, and Columbia counties. One former population in Georgia is known to have been extirpated. Although the historic range of relict trillium is unknown, the existing populations were probably much larger (USFWS 1991). More colonies may have been located after the above USFWS population estimates (USFWS 1991).