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

502 CONVALLARIACEAE/MAIANTHEMUM
family level. It is more closely related to other Asparagales families such as the Agavaceae,
Iridaceae and Orchidaceae than it is to many other taxa often put in a broadly defined Liliaceae
(Chase et al. 1995a, 1995b, 1996, 2000; Fay et al. 2000). 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. Molecular evidence indicates that the Convallariaceae
as treated here is closely related to Asparagaceae, Dracaenaceae, and Nolinaceae, and some
studies (e.g., Chase et al. 1995a; Chase et al. 2000; Fay et al. 2000) have suggested that
Dracaenaceae and Nolinaceae should be included in the Convallariaceae (which would otherwise
be paraphyletic). However, since Nolinaceae appears to be a morphologically well-defined
monophyletic group (Bogler & Simpson 1995, 1996), and until the nomenclature of this complex
is settled, we are maintaining the Nolinaceae as a distinct family. Many Convallariaceae
are cultivated as ornamentals, including Clintonia (WOOD-LILIES), Convallaria, Disporum
(FAIRY-BELLS), Liriope (LILY-TURF), Maianthemum (MAY-LILIES), Ophiopogon (LILY-TURF, MONDO-
GRASS), and Streptopus (TWISTED-STALK). Family name from Convallaria, LILY-OF-THE-VALLEY, a
circumboreal genus of three closely related species often treated as a single species (Conran &
Tamura 1998). LILY-OF-THE-VALLEY is a popular ornamental, but � it contains cardiotoxic glycosides
(Burrows & Tyrl 2001). (Latin: convallis, valley, in reference to a favored habitat of one of
the species—Shosteck 1974) (subclass Liliidae—Cronquist; order Asparagales—APG II)
FAMILY RECOGNITION IN THE FIELD: of the three species occurring in East TX two are perennial
herbs with arching to erect-arching, unbranched leafy stems and either axillary inflorescences
of a few drooping flowers or many-flowered terminal panicles; the third is an introduced, cultivated,
acaulescent herb with white or pale purple flowers in a raceme.
REFERENCES: Dahlgren et al. 1985; Shinwari et al. 1994; Conran & Tamura 1998; Rudall et al.
2000a; Yamashita & Tamura 2000; Judd 2003.
1. Plants acaulescent, all leaves basal; leaf blades 1.5 cm or less wide ________________________ Ophiopogon
1. Plants with an erect to erect-arching stem, the leaves cauline; leaf blades 3–8(–13) cm wide.
2. Perianth 0.5–1 mm long, the segments distinct; inflorescences terminal panicles, with 50 or
more flowers; fruits ruby red at maturity; leaves petiolate, the petioles 1–6 mm long _______ Maianthemum
2. Perianth 13–20(–22) mm long, the segments fused nearly to their tips; inflorescences axillary,
with 15 or fewer flowers; fruits blue-black at maturity; leaves sessile to clasping ___________ Polygonatum
MAIANTHEMUM F.H. Wigg.
FALSE SOLOMON’S-SEAL, MAYFLOWER, MAY-LILY
AA genus of 30–33 species (LaFrankie 2002; Judd 2003) of North and Central America, Europe,
Siberia, the Himalayas, China, and Japan. Species are variously terrestrial or epiphytic,
with most being understory herbs in cool moist forests (Judd 2003). The flowers are either
dimerous with four tepals or trimerous with six tepals. Since dimerous flowers are quite unusual
among monocots, the three species exhibiting this characteristic were in the past recognized
as the genus Maianthemum (in the strict sense), while those species with trimerous flowers
were placed in Smilacina. However, we are following LaFrankie (1986a, 1986b, 2002) and
Judd (2003), who consider all the species closely related and treat them in a single genus
(which because of nomenclatural priority must be Maianthemum). According to LaFrankie
(2002) and Judd (2003), the monophyly of a broadly considered Maianthemum is supported
by morphological, chromosomal, and molecular analyses, and the four-tepaled (2-merous) condition
is apparently “the result of anatomical reduction from the 3-merous state.” Some species
are cultivated as ornamentals. According to Yatskievych (1999), the young shoots of some taxa
can be cooked like asparagus, and “the starchy rhizomes of some species were soaked in lye and
then parboiled by Native Americans.” Pollination is apparently by various insects and fruit dispersal
is by birds (Judd 2003). (Latin: Maius, May, and Greek: anthemon, flower—LaFrankie 2002)
REFERENCES: Kawano & Iltis 1966; LaFrankie 1984, 1986a, 1986b, 2002.