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

792 ORCHIDACEAE/ZEUXINE
spheroid, tuber-like swellings to 3 cm long and 15 mm in width which give rise to new plants;
stem tinged with purple; leaves 2–8, bract-like, tinged with purple, broadly ovate to cordate, 10–
15(–20) mm long, 2–15 mm wide, clasping; inflorescence racemose, with 1–6(–rarely more), but
often 3, pedicellate, white to pink flowers borne from the leaf axils; flowers resupinate, usually
lasting only a single day; sepals oblanceolate, 11–15 mm long, 3–4 mm wide; lateral petals
oblanceolate, 11–14 mm long, ca. same width as sepals, arched over the column; lip white with
three parallel, bright green, papillose crests, 10–15(–20) mm long, 6–10 mm wide, with slender
claw, 3-lobed, the lateral lobes � ovate, curved upward, the middle lobe ovate to orbicular, with
a sinuate margin; column ca. 10 mm long, white; pollinia 2, purplish; capsules erect, to 15 mm
long; 2n = 44 (Sheviak & Brown 2002). Leaf mold of hardwood forests, rich sandy soils near
streams; Nacogdoches, Smith (BRIT), Anderson, Jefferson, and San Jacinto (Liggio & Liggio
1999) cos. in the Pineywoods; se Canada (Ont.) and throughout e U.S. w to NE and TX. Jul–Oct
(flowering synchronous and ephemeral). [Pogonia trianthophora (Sw.) Britton, Sterns &
Poggenb., T. trianthophora var. schaffneri Camp] Flowering is unpredictable: in some seasons
many plants in a colony will appear above ground while in other seasons scarcely any will appear
(Luer 1975). The roots exist saprophytically below ground in symbiosis with a fungus
(Luer 1975) and can exist for years without sending up a flower stalk (Summers 1987). Mass
flowering of a colony (all mature buds opening at the same time on the same day), apparently
based on temperature or other environmental cues, has been reported (Luer 1975; Keenan 1988,
1992). Typically a plant will have one or two flowers open at a time, and the individual flowers
are usually open for only a single day (Keenan 1988, 1992), but sometimes 2–4 days near the w
limit of the species (Medley 2002). The common name NODDING-POGONIA results from the
pedicels not rigidly supporting the weight of the flowers (Luer 1975). Pollination is by small,
often halictid, bees (Medley 1979; Catling & Catling 1991b). m/306
ZEUXINE Lindl. SOLDIER’S ORCHID
AA genus of 30 species (Ackerman 2002b) of tropical and warm areas of the Old World; some
species are cultivated as ornamentals. (Greek: zeuxis, yoking or joining, probably in reference to
the partial fusion of the lip and column, or possibly from the pollinia growing together in some
species—Sheehan & Sheehan 1995)
REFERENCES: Ames 1938; Luer 1972; Sheehan & Sheehan 1995; Liggio & Liggio 1999; Ackerman 2002b.
Zeuxine strateumatica (L.) Schltr., (band, company, or army, probably in reference to the resemblance
of a number of the erect plants to a company of soldiers—Luer 1972), ZEUXINE ORCHID,
SOLDIER’S ORCHID. Erect terrestrial herb 4–25 cm tall, perennial, but can act as an annual, rhizomatous,
with new plants forming from buds on the rhizomes; stems often purplish; leaves 5–
12, sheathing the stem, linear-lanceolate, to 8(–9) cm long, 3–8 mm wide, keeled; inflorescence a
densely-flowered terminal spike with up to 50 flowers (tiny plants may have only 1 or 2 flowers);
flowers white except for bright yellow to orangish lip; sepals and lateral petals similar,
ovate to ovate-lanceolate, 4–7 mm long, 1.5–3 mm wide, the dorsal sepal and lateral petals converging
to form a hood; lip ca. 4 mm long and 3 mm wide, rounded and dilated apically, adnate
at base to base of column; column ca. 1.5 mm long and wide; pollinia yellow; capsules semierect,
ca. 7 mm long and 6 mm wide; 2n = 22–64, 30–56, 50, 100 (Sheviak & Brown 2002). Weed
in such habitats as flower beds, lawns, and gardens; Brazos (H. Wilson, pers. comm.) and Harris
(TAMU; Liggio & Liggio 1999) cos.; a report of a Montgomery Co. locality (Liggio & Liggio 1999)
is apparently incorrect (L. Brown, pers. comm.); AL, FL, GA, LA, MS, SC and TX. Dec–Jan. Native
of Asia. This species is thought to have first arrived in North America (FL) in a shipment of centipede
grass (Eremochloa ophiuroides) seed in 1927 (Sheehan & Sheehan 1995); it is now widespread
in peninsular Florida and into Georgia, and it was first discovered in TX in 1988 growing
in a mulched flower bed (Brown & Gandhi 1989; Liggio & Liggio 1999). Liggio (pers. comm.) has
heard of other unconfirmed reports and suggests that the species will possibly become more