keys to the vascular plants of east texas - Botanical Research ...

TRILLIUM/TRILLIACEAE
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Schilling 2002; Judd et al. 2002). Species of all the genera are cultivated (Zomlefer 1996). While
the traditional view was that there were 2 genera (Paris, Tr illium) in the family, more recently,
different authors have recognized either 4 genera (e.g., Tamura 1998d) or only a single genus
(Judd. et al. 2002). However, the most recent study, based on both molecular and morphological
data, suggests that 6 genera may be warranted (Farmer & Schilling 2002). The genera have
been variously treated in terms of family affiliation—since 1846 members of the family have
been placed in five different families (Farmer & Schilling 2002). Some authorities have put
them in a very broad and clearly polyphyletic (but practical) Liliaceae (e.g., Correll & Johnston
1970; Cronquist 1988). However, based on phylogenetic analyses, we are following Dahlgren et
al. (1985), Zomlefer (1996), Tamura (1998d), Judd et al. (1999, 2002), and Farmer and Schilling
(2002) in recognizing a narrowly defined Trilliaceae; as such, the family is monophyletic (Kato
et al. 1995b). The family is related to the Melanthiaceae (in the narrow sense as treated here),
and additional research is needed to clarify that relationship (Zomlefer 1997a). Indeed, some recent
molecular and morphological analyses (e.g., Chase et al. 2000; Fuse & Tamura 2000;
Rudall et al. 2000b; Zomlefer et al. 2001) have suggested that Trillium and related genera be included
in Melanthiaceae, a course followed by the Angiosperm Phylogeny Group (APG II 2003).
While clearly related to that family, such a treatment of Trillium and allies is, however, problematic
in that it groups together plants of radically different morphologies (1 showy versus
many small flowers, 3 bracts in a whorl versus basal leaves, berry fruit versus capsules, etc.). In
fact, “there are no morphological synapomorphies that unite these two groups as separate from
other Liliaceous plants” (Farmer & Schilling 2002). As a result, we are taking what we consider
to be an intermediate, practical approach in recognizing the Trilliaceae as a separate family. For
a detailed discussion of the groups formerly treated as Liliaceae in the broad sense, see the family
synopsis of the Liliaceae (here treated in a restricted sense) on page 726. Some members of
the Trilliaceae have been used medicinally (e.g., species of Paris, Trillium), and Paris quadrifolia
L., HERBA PARIS, native to Europe and n Asia, is a well known medicinal and poisonous plant still
used in homeopathy “for neurological disorders, gout, rheumatism, and other inflammatory
maladies” (Zomlefer 1996); � its fruits are considered very poisonous (Zomlefer 1996). (subclass
Liliidae—Cronquist; order Liliales—APG II)
FAMILY RECOGNITION IN THE FIELD: plants with leaves (actually leaf-like bracts) in a single whorl
of 3 at summit of the stem, flower 1 per plant, 3 showy petals, and fruit fleshy and berry-like.
REFERENCES: Dahlgren et al. 1985; Kato et al. 1995b; Zomlefer 1996; Tamura 1998d; Fuse &
Tamura 2000; Rudall et al. 2000b; Farmer & Schilling 2002.
TRILLIUM L. WAKE-ROBIN, BIRTHROOT,
TRILLIUM, TOAD-SHADE, SQUAW-ROOT, CARRION-FLOWER
Perennial rhizomatous herbs, lacking the odor of onion or garlic; stems unbranched, erect or
nearly so, glabrous or slightly scabrous; leaf-like bracts (often referred to as leaves since they are
the primary photosynthetic structures of the plant) usually 3, in a distinctive whorl at summit
of stem, glabrous, with net venation; flowers perfect, solitary, sessile or pedicelled, at summit of
stem with leaf-like bracts; perianth parts 6, in two series, free, the outer series (sepals) green or
with some purplish pigmentation, persistent; inner perianth segments (petals) white to pink,
purple, greenish, or yellow, not persistent; stamens 6; anthers linear, ca. as long as or longer than
filaments; ovary superior; fruits fleshy, berry-like.
AA genus of 43 species (Case 2002) with some authorities recognizing up to ca.48–50 species
(Zomlefer 1996; Tamura 1998d; Kazempour Osaloo et al. 1999). They are rhizomatous herbs with
an apical whorl of three leaf-like bracts and a single flower and are disjunctly distributed in w
North America, e North America, and the Himalayas to e Asia, with the center of diversity in
the Appalachian mountain region (Zomlefer 1996; Tamura 1998d). The genus is often considered
an Arcto-Tertiary element (Tamura 1998d), and according to Kazempour Osaloo et al.