Corallorhiza odontorhiza (Willd.) Nutt.
Late coral-root, autumn coral-root
The specific epithet odontorhiza is from the Greek meaning "tooth-root,"
in reference to the tooth-like swollen base of the stem.
DESCRIPTION: Plant
glabrous, 10-20 cm tall, arising from a branched, coralloid rhizome. Base
of the stem swollen into a tooth-like pseudobulb. Leaves reduced
to several bladeless bracts sheathing the stem. Inflorescence a lax
terminal raceme, 5-13 flowered; each flower subtended by a small, linear-lanceolate
bract. Sepals linear-lanceolate, 3-4.5 mm long and 1-1.5 mm wide,
madder-purple, typically green at the base. Petals oblanceolate,
about 4 mm long and 1.5 mm wide, colored as sepals. Labellum clawed,
obovate to orbicular; 2.5-4 mm long and 3-5 mm wide, the margin undulate
or crenulate, the base of the central portion with two fleshy ridges, white
spotted with dark purple. Flowers may be cleistogamous, in which case all
flower parts are connivent. In chasmogamous flowers, the sepals and petals
are loosely connivent and form a hood over the column.
SIMILAR SPECIES: Corallorhiza odontorhiza could possibly be confused
with a late-flowering specimen of C. maculata,
although C. odontorhiza typically blooms after C.
maculata is done flowering. The two can be easily be separated by
the shape of the labellum, which is undivided in C. odontorhiza,
but is divided in three parts in C. maculata.
HABITAT: Corallorhiza odontorhiza can be found in a variety of
forested upland habitats, although the woods it grows in are typically mesic,
and only occasionally dry.
FLOWERING DATES: August 20-September 25.
POLLINATION: The flowers of Corallorhiza maculata come in two
forms: the typical cleistogamous form, and a less common chasmogamous form.
While the cleistogamous form is self-pollinating, I am unsure whether this
is the case for the chasmogamous form. It is possible that the chasmogamous
form is insect-pollinated. A study of the pollination biology/breeding system
of the chasmogamous form might hold some potential for increasing our understanding
of the evolution of cleistogamy.
WI DISTRIBUTION: 
U.S. DISTRIBUTION:
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