Corallorhiza trifida Chatelain
Early coral-root, northern coral-root, pale coral-root
The specific epithet trifida is from the Latin meaning "divided
in three parts," in reference to the tripartite labellum.
DESCRIPTION: Plant glabrous,
8-35 cm tall, arising from a branched, coralloid rhizome. Leaves
reduced to several bladeless bracts sheathing the stem. Inflorescence
a dense to lax terminal raceme, 5-20 flowered; each flower subtended by
a small, lanceolate bract. Sepals linear-lanceolate, 3-6 mm long
and 1-2 mm wide, yellowish-green to green, sometimes tinged with purple.
Petals similar to sepals, connivent with dorsal sepal and forming
a hood over the column. Labellum 3-lobed, obovate to oblong; 2.5-4
mm long and 2-3 mm wide, the margin undulate or crenulate, the base of the
central portion with two fleshy ridges, the lateral lobes of the labellum
small and acute, white or white spotted with dark purple.
SIMILAR SPECIES: Corallorhiza trifida is most likely to be confused
with other species of Corallorhiza. It can be separated from C.
odontorhiza and C. striata by its undivided labellum. C. trifida
is most easily separated from C. maculata
by looking at the innervation of the lateral sepals: they are prominently
three-nerved in C. maculata, while they
have only a single nerve in C. trifida. The two can also be separated
by overall size (C. maculata is larger)
and blooming date (C. maculata generally
HABITAT: In northern Wisconsin, Corallorhiza trifida is found
in a wide variety of habitats, from Thuja bogs to upland forest, both deciduous
and coniferous. In the southern part of its range, it is usually restricted
to moist or boggy sites.
FLOWERING DATES: May 15-July 1.
DISCUSSION: Taxonomists have sometimes recognized two varieties of
Corallorhiza trifida: var. verna with green to yellowish green
flowers and unspotted labella, and var. trifida, with purplish-tinged
flowers and purple-spotted labella. These two varieties intergrade, however,
so they are not recognized here. Despite this, I should point out that most
plants in Wisconsin would probably be assigned to var. verna.
WI DISTRIBUTION: U.S. DISTRIBUTION:
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