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

746 MELANTHIACEAE/ZIGADENUS
addressed these issues, showing that Melanthium is derived from within Veratrum, and supporting
the monophyly of Veratrum in the broad sense. Therefore, treatment of Melanthium
within Veratrum now seems most appropriate. � Veratrum (FALSE or WHITE HELLEBORE) species
have long been important medicinally and as poisonous plants. They have been used medicinally
since ancient times in Eurasian folk medicine, by various Native American tribes, and
from the early 1800s until recently by medical doctors for the control of hypertension; they
have also been used in sorcery, mystical rites, as crow poisons, and as insecticides (Kupchan et
al. 1961; Zomlefer 1997a; Burrows & Tyrl 2001; Alm 2002). The hypotensive, teratogenic, and/or
neurotoxic properties are the result of Veratrum alkaloids (e.g., veratradine, veratramine), a
physiologically powerful group of very complex molecules. Approximately 100 of these compounds
have been isolated, even though relatively few species have been thoroughly analyzed
(Zomlefer et al. 2003). (Latin: vere, true, and aater, black, in reference to the black rhizomes
found in some species—McNeal & Shaw 2002)
REFERENCES: Zimmerman 1958; Bodkin 1978, 1998; Zomlefer 1997a; Tamura 1998d; Zomlefer et
al. 2001; Bodkin & Utech 2002; McNeal & Shaw 2002; Zomlefer et al. 2003.
Veratrum virginicum (L.) W.T. Aiton, (of Virginia), BUNCHFLOWER. Perennial, short rhizomatous
herb lacking the odor of onion or garlic; stem base slightly bulbose, with brown fibers derived
from old leaf bases; stem � erect, 0.6–1.5(–2) m tall, downy or scurfy above; leaves mostly basal,
those on the stem reduced and mostly bract-like; basal leaves 20–50(–80) cm long, 4–32 mm
wide, broadly linear; inflorescence a terminal panicle; pedicels 4–22 mm long, subtended by
small bracts, these densely floccose on margins and lower surfaces; flowers perfect or sometimes
those near tip of inflorescence functionally staminate, numerous; tepals 6, 5–13 mm long,
fused at the base, clawed, with a pair of yellow to greenish brown, nectariferous glands at base
of � ovate blade portion, whitish to pale yellow, turning greenish yellow or reddish purple; claw
< 1/2 as long as blade; stamens 6, attached near or above middle of each claw; styles 3; ovary
superior; fruit a 3-lobed capsule 10–18 mm long; seeds flat; 2n = 16 (Bodkin & Utech 2002).
Bogs, swales, savannahs, meadows, forest margins; Angelina, Jasper (ASTC), Anderson, Jefferson,
and Milam (Turner et al. 2003) cos. in the Pineywoods and Post Oak Savannah; widespread
in e U.S. w to KS, OK, and TX. May–Jul. [Melanthium dispersum Small, Melanthium virginicum
L.] This species contains a number of poisonous alkaloids (Yatskievych 1999). � m/306
ZIGADENUS Michx.
DEATH-CAMAS, POISON-SEGO, STAR-LILY, ZYGADENE
A A monotypic genus of the se U.S. represented only by Z. glaberrimus. Recent chromosomal,
molecular, and morphological studies (Zomlefer et al. 2001; Zomlefer & Judd 2002) have necessitated
significant changes in generic circumscription of the tribe Melanthieae (which includes all
East TX members of the family). In the past, Zigadenus has been variously circumscribed—
Zomlefer (1997a) provisionally recognized 17 species, included the monotypic segregate
Amianthium, and noted that the genus represents a “heterogeneous, non-monophyletic grouping”
needing study. Tamura (1998b) circumscribed the genus more narrowly (ca. 10 species) and
excluded Amianthium. Schwartz (2002) had a more inclusive view, recognizing 18–22 species. In
all of these conceptions, the genus was a heterogeneous assemblage of only distantly related species.
This is a clear example of new research requiring scientific names to be changed (despite
some nomenclatural confusion). Extensive recent research (Zomlefer et al. 2001) has shown that
Z. glaberrimus is an isolated taxon on a separate evolutionary branch from the rest of the tribe—it
thus has to be recognized as a separate genus. Because Z. glaberrimus is the type species of
Zigadenus, different generic names have to be used for the other groups of species previously recognized
in the polyphyletic Zigadenus (Zomlefer & Judd 2002). For example, Z. densus and Z.
nuttallii are now treated in Stenanthium and Toxicoscordion respectively. Previously sometimes
spelled Zygadenus, an orthographic variant that does not have nomenclatural priority. (Greek:
zygos, a yoke, and aden, a gland, referring to the glands on the tepals sometimes being in pairs)