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

770 ORCHIDACEAE/MALAXIS
Listera australis Lindl., (southern), SOUTHERN TWAYBLADE, LONG-LIP TWAYBLADE. Inconspicuous
delicate herb 8–20(–29) cm tall; roots few, fibrous; stems erect, purplish green, glabrous; leaves
2(–3), opposite or subopposite, borne at stem apex, sessile, ovate to elliptic-ovate, 1.3–3.5(–4) cm
long; inflorescence a loose terminal raceme of 5–25 greenish purple or reddish purple,
pedicelled flowers; peduncle and rachis � glandular pubescent; bracts to 2 mm long and 1 mm
wide; flowers resupinate; perianth parts persisting as capsules mature; sepals ovate, ca. 1.5 mm
long and 1 mm wide; lateral petals oblong, obtuse, ca. 1.5 mm long and 0.5 mm wide, recurved;
lip 6–12 mm long, linear, auricled on each side basally, split in the distal 1/3–3/4 into two filamentous
lobes (and thus appearing distinctly 2-pronged); column minute, 0.5–1 mm long and
wide; pollinia 2, yellow; capsules borne horizontally, ovoid, to 8 mm long and 5 mm wide. In
humus and among mosses in dense shade of low woods and ravines, bogs, “usually in association
with rhizomes of cinnamon fern (Osmunda cinnamomea) and royal fern (O. regalis)”
(Magrath & Coleman 2002); J. Liggio (pers. comm.) has observed that the species is also found
where no Osmunda is present; widespread in the Pineywoods; se Canada and e U.S. from VT s to
FL w to OK and TX. Feb–Jun. [Ophrys australis (Lindl.) House] Leaves appear in late winter, allowing
the plants to make use of the abundant sunlight reaching the forest floor before the deciduous
trees of the canopy develop their leaves (Liggio & Liggio 1999). This species is inconspicuous
and easily overlooked. m/291
MALAXIS Sol. ex Sw. ADDER’S-MOUTH
AA subcosmopolitan genus of ca. 250 species of usually small, delicate, terrestrial herbs, with
greatest diversity in Asia and the East Indies (Catling & Magrath 2002). A portion of the column
produces a microscopic droplet of sticky fluid which comes in contact with the pollinia.
When a minute insect reaches behind the column for nectar, it touches the droplet and upon
leaving, it withdraws the pollinia now glued to its head or proboscis. The pollinia are subsequently
transferred to another flower (Luer 1975). Pollination of the tiny flowers of some species
is by fungus gnats (Catling & Catling 1991b). The common name is derived from the apparently
bifid lip, supposedly resembling the bared fangs of a tiny snake (Luer 1975). Malaxis
wendtii Salazar, known from Mexico and Trans-Pecos TX, was named in 1993 honoring Dr. Tom
Wendt, a student of Mexican phytogeography and floristics and botanist at the Univ. of TX at
Austin (Salazar 1993). (Greek: malaxis, a softening, from malaco, soft or delicate, either in reference
to the soft succulent consistency of the leaves or to the fragile nature of some members of
the genus (Luer 1975; Summers 1987)
REFERENCES: Ames & Schweinfurth 1935; Luer 1972, 1975; Catling 1991; Catling & Magrath 2002.
Malaxis unifolia Michx., (single-leaved), GREEN ADDER’S-MOUTH, ONE-LEAF MALAXIS, ONE-LEAF
ADDER’S-MOUTH, GREEN MALAXIS. Plant 3–30(–55) cm tall (usually shorter), glabrous; roots few,
fibrous; stems swollen at base into a pseudobulb 0.5–2 cm in diam.; leaf solitary (rarely 2),
bright green, ovate to ovate-lanceolate, 1.6–10 cm long and 0.5–5(–6.5) cm wide, keeled beneath,
the base sheathing the stem; inflorescence a solitary terminal raceme with 10–50(–160) tiny
flowers; floral bracts 1.4 mm or less long; flowers green, resupinate; sepals 1.1–1.9(–2.2) mm long;
lateral petals thread-like, recurved, 0.8–1.7(–3) mm long 0.1–0.3 mm wide; lip 1.1–2.3 mm long,
1–2.2 mm wide, 3-toothed, the middle tooth short and the lip thus appearing bifid; column
minute, 0.4–0.6 mm long; pollinia 4; capsules subglobose to ellipsoid, to 8 mm long and 4 mm
wide. In humus on moist wooded slopes along streams, ravines, and in mixed pine-hardwood
forests, also on margins of baygalls, acidic soils; Pineywoods and Red River Co. (Liggio & Liggio
1999) in Red River drainage; e Canada and throughout e U.S. w to MN, OK, and TX. Apr–Jun.
[Achroanthes unifolia (Michx.) Raf., Microstylis unifolia (Michx.) Britton, Sterns & Poggenb.]
m/292