>From nrach@lgc.com Fri Apr  4 10:05:59 1997
Date: Fri, 4 Apr 1997 11:08:22 -0600 (CST)
From: Nina Rach <nrach@lgc.com>


I wrote this yesterday and handed it out at the HOS meeting last night:

Epipactis gigantea Douglas ex Hooker -- General Information and Cultural Notes
by Nina Rach, April 1997

General:
The name Epipactis derives from a classical name used by Theophrastus (circa
350 B.C.) for a plant used to curdle milk. About 25 species found worldwide,
mostly in Europe (15 species) and Asia. Two species are found in the U.S. -
E. gigantea and E. helleborine.  The latter is thought to have arrived in
North America from Europe in the 19th century and grows in the northeastern
U.S.

Epipactis gigantea is virtually always found in wet places, commonly known as
the "stream orchid," "giant helleborine," "chatterbox," and "false lady's
slipper."  It's the most common native orchid in California and ranges to west
Texas, northern Mexico, and southern Canada. There are usually 10 or more
green, ovate-lanceolate leaves per plant, alternating on the stem, each from
5-11 cm wide and up to 25 cm long. There is a variety native to California
that has wine-red leaves. In cultivation, the plants usually reach 30-50 cm
tall.  The foliage is deciduous - dies back in the fall. After the foliage
turns brown, the new shoots begin to spread away from the rhizome.

Plants bloom to about 1 meter high, with 12-20 flowers per inflorescence. The
flowers are 4 to 4.5 cm across (up to 5.5 cm), and usually face the same
direction. Sepals are usually dark green, petals rose with dark veining. The
(usually red) lip is deeply three-lobed, hinged in the middle, with yellow
lateral lobes. The epichile is elongated and vibrates in slight breezes (hence,
the "chatterbox"orchid) and the ovary is straight.  Flowers have four pollinia.
White flower forms and peloric forms are known. Blooming season is early March
to early October; the species blooms in 39 months from seed.

Habitat:
Found from sea level to 2600 m, always with a constant source of water at the
roots, including wet cliff-faces, salty beaches, road-cuts, mountain bogs, hot
springs, and sandbars in streams.The rhizomes are slender. One of the known
pollinators is the Syrphid fly.

Culture:
Mix: peat moss, sand, perlite, some charcoal, humus.  You may also add powdered
lime and bonemeal. The colony of plants at Kew Gardens is grown beside a small
stream in a rock garden, in peat, loam, and leaf mold compost in partial shade,
along with dactylorhizas and Skunk Cabbage. A colony is also growing at the
Geneva Botanic Garden in a rock garden (drier and sunnier than Kew) along with
Cypripedium reginae.

Best to repot just as plants are breaking dormancy; however, Carson Whitlow
recommends handling plants in the autumn, just before dormancy.  Tip of leading
growth bud should be level with top of compost.

Keep pot in a saucer or trough of water, in bright light.  Can grow outdoors in
Houston year-round; might benefit if refrigerated or kept cool in some way over
the winter.  The plants will not tolerate a hard freeze. Suitable for the
Holman and Whitlow artificial bog techniques (see Cribb & Bailes), or moist
rock gardens.

--------------------------------------------------------------------------------

References:

The Wild Orchids of California, by Ronald A. Coleman, Cornell University Press
(1995), 201 pp.

Hardy Orchids, by Phillip Cribb and Christopher Bailes, Timber Press (1989),
162 pp.

The Native Orchids of the United States and Canada, by Carlyle A. Luer, New
York Botanical Garden (1975), 361 pp.

Species-level and population-level patterns of genetic variation in the
riparian orchid, Epipactis gigantea Dougl. ex Hook. (Orchidaceae), by Alan
Thornhill, Ph.D. dissertation. (1996), submitted to the American Journal of
Botany.
-------------------------------------------------------------------------------