E-Flora BC: Electronic Atlas of the Flora of British Columbia

Spiranthes romanzoffiana Cham.
hooded ladies' tresses
Orchidaceae (Orchid family)

Introduction to Vascular Plants

© Rosemary Jorna  Email the photographer   (Photo ID #46912)

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Distribution of Spiranthes romanzoffiana
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Hooded ladies' tresses (Spiranthes romanzoffiana) is a widespread species in North America and is found throughout Canada and the United States, except for the southeastern states (USDA 2010). In British Columbia, this species is frequent below 55 degrees N and infrequent north of that. Across the province it is found in a variety of habitats, including dry to moist forests, bog forests, and open (moist) meadows at elevations ranging from sea level (Boundary Bay Park) to 1200+ m. This is a perennial species,10-50 cm tall, with long fleshy tuberous roots. Leaves are primarily basal with some stem leaves that grade into short, sheathing bracts. Flowers are distinctive, white and spiralling on the stem, often in vertical rows.Flowers appear from mid-July to mid-August at low elevations, but plants have been observed in flower in September at higher elevations. This species is very similar to Ute ladies' tresses (Spiranthes diluvialis), a recently found species of ladies' tresses in the province.

Species Information

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Perennial herb from long, fleshy, tuberous roots, with a few fibrous ones; stems 10-50 cm tall, leafy below, bracted above.
Basal linear to linear-lanceolate, 5-20 cm long, usually 5-10 mm wide, some stem leaves but soon reduced into short, sheathing, lance-shaped bracts above.
Inflorescence a dense, bracted, cylindrical spike, the flowers creamy-white to greenish-white, usually in three somewhat spiralling vertical rows, the bracts 10-20 mm long, about the length of the flowers, whitish or pale green; sepals and petals to 12 mm long, the lateral sepals narrowly egg-shaped, the tips bent back, the upper sepal and petals about equal in length, forming a curved, tubular hood 7-12 mm long; lip egg-shaped, about length of sepals, veined, strongly curved downward, constricted above the middle, widened below into an egg-shaped, terminal lobe; spur absent; column 2-4 mm long.
Capsules, to 10 mm long.

Source: The Illustrated Flora of British Columbia

USDA Species Characteristics

Flower Colour:
Blooming Period:
Mid Summer
Fruit/Seed characteristics:
Colour: Brown
Present from Summer to Fall
Source:  The USDA

Habitat / Range

Dry to moist forests, bog forests, bogs, meadows, and open depressions in the lowland to montane zones; frequent throughout BC, south of 55 degrees N, infrequent northward; N to AK, YT and NT, E to NF and S to ME, MA, PA, OH, IN, IL, IA, SD, NM, AZ and CA; British Isles.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Spiranthes romanzoffiana

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class




Elevation (metres) 87 934 2110
Slope Gradient (%) 0 3 55
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
25 230 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
0 6 8
Modal Nutrient Regime
Number of field plots
 species was recorded in:
Modal BEC Zone Class
All BEC Zones (# of stations/zone) species was recorded in: BWBS(35), CDF(2), CWH(15), ESSF(32), ICH(19), IDF(3), MH(2), MS(10), SBPS(5), SBS(25), SWB(1)


The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is not evaluated, unknown or variable.

Synonyms and Alternate Names

Ibidium strictum (Rydb.) House
Spiranthes romanzoffiana var. porrifolia (Lindl.) Ames & Correll
Spiranthes stricta Rydb.

Taxonomic and Nomenclatural Links

Additional Photo Sources

Species References

Bjork, Curtis, Terry McIntosh and Ron Hall. 2008. Vascular plants new to British Columbia from the southern Okanagan Valley. Botanical Electronic News 391.

General References