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

500 CONVALLARIACEAE
key. While recognizing it as a distinct species, Faden (2000b) indicated that this is “… clearly
Anderson and Woodson’s weakest species, and D.T. MacRoberts (1979) may be correct in treating
it as a variety of Tradescantia ohiensis.” This species can be cultivated year-round in greenhouses,
since the plants apparently do not require a winter dormancy (Faden 2000b).
Tradescantia reverchonii Bush, (for Julien Reverchon, 1837–1905, a French-American immigrant
to Dallas and important botanical collector of early TX), REVERCHON’S SPIDERWORT, GRASS-VIO-
LET. Roots thick, fleshy, conspicuously felty with red-brown hairs easily visible to the naked
eye; stems 30–105 cm tall, erect or ascending, simple or infrequently branched, usually rather
densely pilose with somewhat matted or tangled hairs; sepals with eglandular or both
eglandular and glandular hairs; petals bright blue (rarely rose or white). Sandy soils, open
woods; widespread in the s and e parts of East TX, also collected at Dallas by Reverchon
(Mahler 1988) but not found there since; also Gulf Prairies and Marshes, South TX Plains, and e
Edwards Plateau; AR, LA, and TX. Mar–Jul.
Tradescantia subacaulis Bush, (almost without a stem), STEMLESS SPIDERWORT. Roots tuberousthickened;
stems spreading, 10–35 cm long, densely matted-pilose throughout; sepals with
glandular and eglandular hairs; petals usually bright blue, occasionally pink. Loose sandy soils,
open woods or open ground; widespread in e 1/2 of TX; endemic to TX (Faden 2000b; Carr
2002b, 2002c). Late Mar–Jun. E
Tradescantia tharpii E.S. Anderson & Woodson, (for Benjamin Carroll Tharp, 1885–1964, botanist
at Univ. of TX and author of Structure of Texas Vegetation East of the 98th Meridian),
THARP’S SPIDERWORT. Plant long-pilose throughout, usually densely so; stems 2–7 cm tall in
flower, to 20(–30) cm in fruit; stems rarely branching, often initially acaulescent; sepals with
only eglandular pubescence; petals deep rose or purple, sometimes blue. Sandy clay or rarely
silty clay soils, rocky prairies, open woods, or open ground; Collin, Denton, and Dallas (BRIT)
cos. in the Blackland Prairie; while we have seen specimens from only a few counties, Hatch et
al. (1990) cited vegetational areas 4, 5, 7, and 8, and the range map in Faden (2000b) shows the
species occurring throughout East TX; KS, MO, OK, and TX. Late Mar–Apr.
CONVALLARIACEAE Horan.
LILY-OF-THE-VALLEY FAMILY
Rhizomatous perennial herbs, acaulescent or with arching to erect-arching stems; leaves all
basal or cauline; inflorescences terminal or axillary; flowers perfect, 3-merous; perianth of distinct
or fused segments; stamens 6; ovary superior or partly inferior; fruit a berry.
AA small family (17 genera and 130 species) found in North and Central America, Europe, and
Asia (Conran & Tamura 1998). The family placement of the genera treated here as
Convallariaceae has been extremely variable. Many authorities in the past have put them in a
broadly defined and clearly polyphyletic (but practical) Liliaceae (e.g., Correll & Johnston 1970;
Cronquist 1988; Diggs et al. 1999) based on superficial similarities in flower structure to that of
the genus Lilium. However, molecular analyses (Chase et al. 1995a, 2000; Fay et al. 2000) leave
little doubt that the group belongs in order Asparagales. Judd et al. (1999) and Yamashita and
Tamura (2000) placed the genera in the Convallariaceae, while Rudall et al. (2000a), Judd et al.
(2002), and Judd (2003) treated them in a broadly interpreted Ruscaceae. More recently, the
Angiosperm Phylogeny Group (APG II 2003) suggested placing them either in Ruscaceae or in
a very broadly defined Asparagaceae (along with such families as Agavaceae). While placement
in Asparagales now seems clear, there has been disagreement in molecular analyses of the
complex that could possibly affect family circumscription (e.g., Rudall et al. 2000a; Yamashita
& Tamura 2000). Until taxonomy of the group is more settled, we are following Conran and
Tamura (1998) and Yamashita and Tamura (2000) in recognizing the Convallariaceae at the