1. Tipularia discolor (Pursh) Nutt. (crane‑fly orchid)
Pl. 118 g, h; Map 488
Plants
with 2 or 3 ovoid, tuberous corms, these usually connected by short rhizomes.
Flowering stems 30–60 cm long, with 20–40 flowers in racemes, the stem leaves
reduced to a few sheathing bracts. Basal leaf 1, from the terminal corm, the
petiole to 4 cm long, the leaf blade 5–10 cm long, ovate‑triangular to
heart‑shaped, glabrous, herbaceous, and often somewhat pleated, dark
green above, purple beneath. Sepals and lateral petals similar, positioned
asymmetrically with 1 petal overlapping the uppermost sepal, 4–8 mm long,
narrowly oblanceolate, greenish purple. Lip 4–8 mm long, 3‑lobed, the
middle lobe linear with 2 small notches at the tip, pale purple. Spur 15–22 mm.
Column 3–4 mm long, white. Stamen 1, staminodes lacking. Capsules pendant,
10–12 mm long, elliptic in outline, not strongly ribbed. July–August.
Uncommon,
restricted to Crowley’s Ridge and the rest of the Mississippi Lowlands Division
(eastern U.S. west to Texas). Moist soil of mesic forests on stream terraces
and on tops of shallow sand dunes.
This
species was reported for Missouri relatively recently (Pelton, 1989), and the
state is at the northwestern edge of its distribution. There is some evidence
that T. discolor is expanding its range in recent years (Homoya, 1993),
and it is unknown whether the Missouri colonies are part of this phenomenon.
As
in Aplectrum, plants of Tipularia alternate vegetative and
reproductive growth. Leaves are produced in the fall and overwinter, generally
withering in June as the flowering stems begin elongating. The dangling flowers
resemble crane flies, but unlike other orchids, which rememble their
pollinators, this species is pollinated by noctuid moths.