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

TRIPHORA/ORCHIDACEAE
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an example of an e Asia-e North America disjunction; this distribution pattern is discussed under
the genus Brachyelytrum (Poaceae). (Latin: tippula, water-spider, from Tipula, the genus of
insects including crane-flies, in reference to the resemblance of the flowers to crippled craneflies
in flight—Luer 1975)
REFERENCES: Luer 1972, 1975; Stoutamire 1978; Whigham & McWethy 1980; Snow & Whigham
1989; Catling & Catling 1991a; Catling & Sheviak 2002.
Tipularia discolor (Pursh) Nutt., (of different colors, reportedly because of the differing colors of
the two leaf surfaces—Brown 2002a), CRANE-FLY ORCHID, CRIPPLED CRANE-FLY, ELFIN-SPUR. Scapose,
terrestrial, glabrous herb 10–60(–65) cm tall; scape arising from end of a series of horizontally
oriented corms, brownish or purplish green; leaf solitary, produced in fall and overwintering,
green, often blotched with purple above, strikingly purple beneath, the whole leaf turning
dull red before being lost in late spring, distinctly petiolate, the blade cordate to ovate-elliptic,
5–10.5 cm long, 2.5–7 cm wide, the petiole 5–11 cm long; inflorescence a loose raceme of 10–40(–
55) flowers, produced in summer after loss of leaf; floral bracts absent; flowers watery purplegreen
(pale green, tinged or mottled with purple), resupinate, asymmetrical, with one petal
overlapping the dorsal sepal; sepals and lateral petals 4–8 mm long, 1–3 mm wide; lip 3-lobed,
the lateral lobes basal, the slender central lobe much longer (5–8 mm), with a slender, basal, �
horizontal spur (10–)15–23 mm long; column (2.5–)3–4 mm long; pollinia 4 (in 2 pairs), yellow;
capsules narrowly ellipsoid, 9–12 mm long. In humus of rich woods, along streams, floodplains,
and on wooded slopes, “often in depressions under sweet gum” (Catling & Sheviak 2002); widespread
in the Pineywoods; e U.S. from MA s to FL w to IL and TX. Jul–Sep. [T. unifolia Britton,
Sterns & Poggenb.] This species is usually found closely associated with beech trees (Ajilvsgi
1979). Out of a large number of plants producing leaves, only a small percentage will produce
inflorescences in a given year (Luer 1975). This is the only North American orchid whose flowers
are not bilaterally symmetrical (Stoutamire 1978; Homoya 1993), and this lack of symmetry can
be explained as “… part of a character complex adapting the flowers to pollinarium attachment
off the visitor midline. …” (Stoutamire 1978). According to Catling and Sheviak (2002), pollination
is “… by noctuid moths [family Noctuidae], the pollinaria attaching to either the left or right compound
eye depending on whether the column of a particular flower is slightly twisted to the left
or to the right.” Anther caps surrounding the pollen masses are retained for a brief period of time
(ca. 8–40 minutes before shriveling and falling off) after removal of the pollen masses by pollinating
moths. The anther caps apparently prevent the pollen masses from attaching to stigmatic surfaces.
The time delay is thought to allow the moth ample time to arrive at a different plant and
thus maximize cross-pollination (Stoutamire 1978; Catling & Catling 1991a, 1991b). m/303
TRIPHORA Nutt. THREE-BIRDS ORCHIDS, NODDING-CAPS
AA New World genus of 25 (Medley 2002) terrestrial woodland species formerly included in
the genus Pogonia. However, the somewhat erect mature anther of Triphora would be atypical
in Pogonia (Dressler 1981), and the two genera differ in chromosome number (Baldwin &
Speese 1957). Tr i p hora and several related genera comprise a difficult to place relict group with
no close allies, and Tr iphora and Pogonia are now considered to be in different subtribes, tribes,
or possibly even subfamilies (Dressler 1981, 1993). According to Medley (2002), “Most species of
Triphora exist in small, scattered populations and exhibit synchronous, ephemeral flowering;
flowers last only one day. Synchrony enhances the chances for fertilization. Isolated flowers are
rarely fertilized.” (Greek: tri, three, and phoros, bearing, in reference to the small number of
flowers (often three), or to the three crests on a three-lobed lip—Luer 1975)
REFERENCES: Luer 1972, 1975; Medley 1979, 2002; Keenan 1988, 1992.
Triphora trianthophora (Sw.) Rydb., (three flower-bearing), THREE-BIRDS ORCHID, NODDING-
POGONIA, BROODING-POGONIA. Erect terrestrial herb 8–25(–30) cm tall, with cylindrical to nearly