north american native orchid journal - at The Culture Sheet

Brown & Folsom: WILD ORCHIDS OF THE WHITE MOUNTAINS OF NEW HAMPSHIRE AND MAINE
SPIRANTHES is a cosmopolitan genus of about 50 species. Treated in the strictest sense it is one of the most easily
recognized genera, but has some of the more difficult plants to identify to species. The relatively slender, often
twisted, stems and spikes of small white or creamy-yellow (or pink in S. sinensis) flowers are universally
recognizable.
Key to the ladies’-tresses, Spiranthes, found within the White Mountains region.
1a plants mid-summer flowering; leaves present at flowering time; inflorescence loosely arranged; flower
flowers spaced out, northerly in distribution.....northern slender ladies’-tresses, Spiranthes lacera var.
lacera
1b plants late summer-autumn flowering...2
2a plants of open shales and grasslands; flowers, ca. 5 mm long, usually arranged in a single rank.....Case’s
ladies’-tresses, Spiranthes casei
2b flowers larger, 8 mm or more in length...3
3a lip constricted in the middle, panduriform.....hooded ladies’-tresses, Spiranthes romanzoffiana
3b lip not constricted in the middle...4
4a entire flower white and/or cream; lateral sepals and petals appressed.....nodding ladies’-tresses,
Spiranthes cernua
4b flower creamy-white; lateral sepals and petals approximate or divergent; lower surface of lip
butterscotch colored.....yellow ladies’-tresses, Spiranthes ochroleuca
Spiranthes casei Catling & Cruise var. casei
Case’s ladies’-tresses
Range: Ontario east to Nova Scotia, south to Wisconsin, northern
Pennsylvania and western Maine
In the White Mountains region: rare and local in the northern areas
Plants: terrestrial, 8-50 cm tall, sparsely pubescent below, inflorescence densely
pubescent
Leaves: 3-5; appearing basal or on the lower portion of the stem; linearoblanceolate,
up to 2 cm wide × 20 cm long; ascending to spreading; leaves
present at anthesis
Flowers: 10-50; in a spike, loosely spiraled with 5 or more flowers per cycle,
nodding from the base of the perianth; floral bracts green; sepals lanceolate;
lateral sepals slightly spreading; petals ovate to oblanceolate; perianth ivory
or greenish-white; lip oblong, 5.0-7.5 mm, the central portion often a
deeper creamy yellow, with thin, fringed margins, the apex truncate;
overall flower size 5 (6-9) mm long
Habitat: dry open sites usually on the Canadian Shield in shaley soils,
road scrapes, or thin-soil grasslands
Flowering period: late August to September
Although plants had been known for many years, it was only in 1974 that
they were described as a species. Formerly these plants were often known
as the ―northern (Spiranthes) vernalis’, a species that grows considerably
further to the south. For a short time plants of S. casei were also known as S.
intermedia, again a totally different plant that is actually a hybrid between S.
vernalis and S. lacera var. gracilis and does not range northward. Plants of S. casei, as
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