Spiranthes lacera (Raf.) Raf. - Slender Ladies' Tresses


 

|  back  | forward |

Spiranthes lacera var. lacera - (image 1 of 4)

 

Taxonomy

Family: Orchidaceae

Habitat

Dry, often sandy fields, open woods and thickets, sometimes in thin soil overlying edges.

Associates

 

 Distribution

Nova Scotia and New Brunswick to Saskatchewan, south to FL and TX. The ranges of the two varieties overlap to some degree.

Morphology

Slender perennial to 40 cm. Basal leaves ovate-elliptic or ovate-lanceolate, petiolate, spreading to form a rosette, present during anthesis in var. lacera but usually absent at that time in var. gracilis, withering shortly after; labellum centrally green or white with green veins, papillate; lateral sepals held perpendicular to the stem, not oblique; flowers inodorous.

Notes

Flowers mid-June to early August for var. lacera and August to September for var. gracilis

Wetland indicator: FAC

These photos are of var. lacera which has a more northern range that reaches its southern limit around southern VA, TN, and MO. Spiranthes lacera var. gracilis flowers later in the year and has flowers more densely arranged on the spike, an inflorescence that is more or less glabrous (vs. sparsely pubescent), and basal leaves that are usually absent at anthesis; it reaches its northern limit around southern NH, central VT, southern WI, and NE.

References

Gleason, Henry A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. Second Ed.
The New York Botanical Garden. Bronx, NY

 

Pace, M.C. and Cameron, K.M. The systematics of the Spiranthes cernua species complex (Orchidaceae): Untangling the Gordian Knot. Systematic Botany, 42(4):1-30.

 


Home

 

 Michael Hough 2017