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

742 MELANTHIACEAE/STENANTHIUM
South TX Plains; in the U.S. this species is known only from TX. Sep–Oct (rarely in spring). This
species has in TX long gone under the name S. drummondii A. Gray (e.g., Correll & Johnston
1970), which is now considered an illegitimate name (TROPICOS 2003). Frame (2002) treated
this species as S. ghiesbreghtii Greenm. (also known from Mexico), but based on molecular
work in preparation (W. Zomlefer, pers. comm.), the U.S. populations likely warrant recognition
as a separate species. According to Frame (2002), in the U.S. this species “grows at or near sea
level and almost exclusively on the Reyosa gravel formation of the Texas Gulf prairie. … In the
late 1930s and early 1940s, it was used in a series of transplantation experiments conducted by
the Texas Agricultural Experiment Stations. This has led to some confusion with regard to its
natural distribution.” Until the nomenclature of this species is clarified, we are following the recent
Flora of North America treatment (Frame 2002) in using the name S. ghiesbreghtii for the
GREEN-LILY.
Schoenocaulon texanum Scheele, (of Texas), TEXAS SABADILLA, TEXAS FEATHER-SHANK. Plant to 55
cm tall; leaves to 60 cm long, mostly 4(–6) mm or less wide; tepals 2.3–4 mm long, greenish
white; capsules 10–15(–19) mm long; 2n = 16 (Frame 2002). Limestone soils, rocky grasslands
and openings in juniper-oak woodlands; Bell, Hays, Travis (BRIT), Comal (ASTC), Bexar (Turner
et al. 2003), and Williamson (Balcones Canyonlands Nat. Wildlife Refuge, C. Sexton, pers.
comm.) cos.; w margin of East TX s to South TX Plains and w through Edwards Plateau to
Trans-Pecos; NM and TX. Mar–Jul (–rarely later after unseasonable rainfall). According to
Frame (2002), “The morphology of Schoenocaulon texanum is peculiarly dependent upon annual
rainfall. Plants of small stature but average bulb size can be readily distinguished as the
products of one or several seasons of lower than normal rainfall. The hallmarks of such plants
are congested racemes, few flowers, these often appearing withered and brown, and ovaries that
do not mature or have perhaps only one small locule ripening to produce a few seeds.” m/297
STENANTHIUM (A. Gray) Kunth FEATHER-BELLS, FEATHER-FLEECE
Perennial, subscapose, glabrous herbs from a slender bulb; leaves crowded near base; inflorescence
a raceme or panicle; flowers perfect and/or staminate; tepals 6, all � alike, greenish white
to creamy white, cream, or yellowish, separate to base, not clawed, glandless or with an obscure
gland at base of each; stamens 6; ovary usually superior or partly inferior; fruit a capsule.
AA genus of 2 or 3 species of the e U.S. (Zomlefer & Judd 2002; Zomlefer & Smith 2002). Recent
chromosomal, molecular, and morphological studies (Zomlefer et al. 2001; Zomlefer &
Judd 2002; Zomlefer & Smith 2002) have necessitated significant changes in generic circumscription
of Stenanthium. Several species previously placed in Stenanthium, as well as several
formerly in Zigadenus, have now been shown to belong in the genus Anticlea (Zomlefer et al.
2001; Zomlefer & Judd 2002; Zomlefer & Smith 2002). Stenanthium gramineum (the type species
of the genus) has been shown to be most closely related to taxa (S. densum, S. leimanthoides
if recognized) previously treated in Zigadenus. This is a clear example of new research requiring
scientific names to be changed (despite some nomenclatural confusion). See further discussion
and references under Zigadenus.
All species of Stenanthium have a chromosome number of 2n = 20 (Zomlefer & Smith 2002).
(Greek: stenos, narrow, and anthos, flower, in reference to the narrow inflorescences or tepals)
REFERENCES: Fernald 1946b; Zomlefer et al. 2001; Utech 2002b; Zomlefer & Judd 2002;
Zomlefer & Smith 2002.
1. Tepals 3–5 mm long, each with an obscure gland near the base; inflorescence a raceme or panicle
5 cm or less wide; pedicels 10–20 mm long; capsules 10–20 mm long ________________________ S. densum
1. Tepals (4–)5–10 mm long, without glands; inflorescence a panicle often > 5 cm wide; pedicels
4–6 mm long; capsules 6–10 mm long _____________________________________________ S. gramineum