Spiranthes romanzoffiana Chamisso

Hooded ladies'-tresses

The specific epithet romanzoffiana honors Nicholas Romanzoff, a Russian minister of state and financial supporter of scientific exploration.


Photo courtesy of Bill Alverson
DESCRIPTION: Plant pubescent above the leaves, 10-35 cm tall (including inflorescence), arising from a cluster of fleshy, slender roots. Leaves 2-3(-5) mostly basal, linear-lanceolate, 7-20 cm long and 0.6-1.2 cm wide, grading into reduced sheathing bracts below the inflorescence. Inflorescence a downy, spicate raceme of 20-40 white flowers, 10-40 cm tall, dense and multi-ranked, each flower subtended by an elongate, ovate-lanceolate bract. Sepals ovate-lanceolate, 6-12 mm long and about 2.5-4 mm wide, sepals connivent with petals to form a hood over the column and labellum, sepals creamy-white. Petals linear-lanceolate to linear, 6-11 mm long and 1-2 mm wide, colored as the sepals and closely appressed to the sepals, tips of sepals and petals reflexed slightly. Labellum pandurate (fiddle-shaped), 7-11 mm long and 3-5 mm wide, creamy-white colored with the central portion marked with greenish lines, the apex strongly bent downwards and the central portion somewhat constricted, the base of the labellum with two small, pubescent calli.

SIMILAR SPECIES:
Spiranthes romanzoffiana is likely to be confused with other species of Spiranthes. Perhaps the most similar species is S. cernua, which frequently grows in the same habitat as S. romanzoffiana. However, the pandurate labellum of S. romanzoffiana easily separates it from S. cernua (and all other species of Spiranthes found in Wisconsin).

HABITAT:
Spiranthes romanzoffiana is typically found in open boggy areas, frequently growing in Sphagnum.

FLOWERING DATES:
July 15-August 25.

POLLINATION:
Catling (1983b) collected halictid bees and bumblebees pollinating Spiranthes romanzoffiana.

DISCUSSION: This species has been reported to hybridize with Spiranthes cernua to form S. X steigeri Correll, although the status of this hybrid is questionable (Case 1987). Regardless, there are two specimens in the UW herbarium that are purported to be S. X steigeri.

WI DISTRIBUTION: U.S. DISTRIBUTION:
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