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Table 1 contains the type species and generic synonymy for the genera included in this family. Takhtajan splits Paris into Paris, Kinugasa Tatew. & Sutô, and Daiswa Raf. Other authors, notably Hara, et al. (1978) recognize both Trillium and Trillidium Kunth. In Species Plantarum published in 1753, Linnaeus named four of the species included in this family: Trillium sessile, T. cernuum, T. erectum, and Paris quadrifolia shown at the top of this page or in Figure 1. He separated the genera based on number of locules and anthers. Other names that have been used for the genera in this family and the rationale for being named are given in Table 2.
The composition and placement of the Trilliaceae has varied since its recognition by Lindley in 1846. It has been afforded tribal status within various families, reincorporated back into the Liliaceae, or elevated to familial status within different orders within the monocots. Takhtajan, alone, placed the family in four different orders (1969, 1980, 1987, 1997). Although Paris and Trillium are always paired when segregated within or from the Liliaceae, two other genera, Medeola L. and Scoliopus J.Torr., are frequently included in the family. Sometimes both taxa are included (Dalla Torre and Harms (1908) and Watson and Dallwitz (1991)), others include only Medeola (Engler, 1888; Melchoir, 1964), and still others include only Scoliopus (Dahlgren, et al., 1985; Brummit, 1992). Clintonia was included by Bentham and Hooker (1883). The additional taxa included in the family are shown in Figure 2. An overview of the placement and composition of this family is given in Table 3.
Recent studies such as those using the rbcL gene (Chase, 1994; Chase, et al., 1995a; Kato, et al., 1995b), chloroplast DNA (cpDNA) restriction-site analysis (Davis, 1994, 1995; Kato, et al., 1995a), and combined morphological-restriction site analysis (Stevenson, 1994; Chase, et al., 1995b) are reinforcing the concept that these taxa are not a part of the Liliaceae (sensu stricto) and should in fact be an independent family. It should be understood that the taxa included in the Trilliaceae are not removed from the Liliaceae alone. The Liliaceae sensu lato is a heterogeneous assemblage of genera united only by the fact that they possess 6 perianth segments, usually 6 stamens, and a 3-carpellate ovary (Smith, 1977). Within the broadly defined Liliaceae there is extensive variation for many features. For example, leaves vary from simple, undifferentiated, and strap-like leaves to having leaves with a distinct petiole and lamina; leaves are alternate, opposite, or whorled; leaves have parallel or palmate venation; the infloresence is a raceme or solitary; flowers are perfect or unisexual; floral symmetry is actinomorphic or zygomorphic; the perianth is composed of tepals or distinct sepals and petals; anthers are basifixed or dorsifixed; the ovary is 3-locular with axilary placentation or unilocular and parietal. It is when the Liliaceae is more narrowly defined as a more homogeneous family that the Trilliaceae, as well as many other well-defined families such as Agavaceae, Amaryllidaceae, Asparagaceae, Melanthiaceae, and Smilacaceae are separated out. The molecular evidence indicates that a narrower definition of Liliaceae is probably more consistent with phylogeny. back to topBack to main Trilliaceae pages
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