Spiranthes lacera var. gracilis (Bigelow) Luer
(redirected from: Spiranthes gracilis (Bigelow) Beck)
|
|
Family: Orchidaceae
Northern Slender Lady's-Tresses
[Neottia gracilis Bigelow, moreSpiranthes gracilis (Bigelow) Beck, Spiranthes gracilis var. gracilis] |
Leaves usually absent at anthesis. Inflorescences loosely to very tightly spiraled, sometimes secund, flowers approximate, mostly without distinct space between proximal flowers (ratio of spike length/flower number less than 2.3), glabrous. Flowers: lip 4-7.5 mm, rounded at apex; central portion green with clearly defined, broad crisp white apron. 2n = 30. Flowering Jul--Oct(--Nov). Dry to moist meadows, prairies, barrens, open woods, dunes, old fields, roadsides, cemeteries, lawns; 0--1100 m; N.S., Ont.; Ala., Ark., Conn., Del., D.C., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Mo., Ohio, Okla., N.H., N.J., N.Y., N.C., Pa., R.I., S.C., Tenn., Tex., Vt., Va., W.Va., Wis. Hybrids of Spiranthes lacera var. gracilis with S. vernalis are known as Spiranthes × intermedia Ames.
Perennial herb 15 - 65 cm tall Stem: single, erect, green, lacking leaves except at base, and usually hairless. Leaves: two to four in basal rosette, spreading, stalked, hairless, non-toothed, 2 - 5 cm long, 1 - 2 cm wide, widely lance-shaped to inversely egg-shaped. The leaves wither and die back before flowering time. Inflorescence: a single, erect, terminal, elongate, obviously spiraled spike of 20 to 50 flowers. The flowers are often arranged in up to four, one-sided spirals with all flowers fairly evenly spaced, and the axis is hairless. Flowers: white, bilaterally symmetric, up to 7 mm long (above ovary), slenderly urn-shaped, with spreading sepals, forward projecting lip with deflexed tip, but lacking a spur at base. The reproductive parts of stamens, stigma and style are fused into a column above the 3 mm long inferior ovary. Sepals: three, petal-like, white, somewhat spreading, to 5 mm long and 1 mm wide, and tapering to pointed tips. Roots: few to several, spreading to descending, slender to stout (mostly up to 0.75 cm diameter). Lateral petals: two, white, to 5 mm long and 1 mm wide, lance-shaped with blunt-angled tips. Lip petal: one, central, lowermost, deflexed at tip, white with wide green or yellowish center (almost extending to tip), 4 - 7.5 mm long, 1 - 2.5 mm wide, egg-shaped to oblong with obviously widened, rounded, crisp wavy-edged tip. The veins along the lip are obscure, but the two, small (up to 1 mm tall), short-pointed, erect, basal projections (calli) are visible. Similar species: Spiranthes lacera var. gracilis can be distinguished from the typical variety, S. lacera var. lacera, because that variety has glandular hairs at least along the inflorescence axis (these hairs stalked and round-tipped), the flowers are much more loosely arranged in the inflorescence and sometimes even appear one-sided, and the darker marking of the lip petal never extends to the tip and typically does not extend much beyond the middle of the lip. Flowering: late August through September Habitat and ecology: Localized to sandy prairies and black oak savannas. Occurence in the Chicago region: native Notes: This variety usually flowers later than the typical variety, which tends to finish blooming when this variety starts to bloom (Case 1987). Etymology: Spiranthes comes from the Greek words spir meaning coiled, and anthes meaning flowers, thus referring to the spiral arrangement of the flowers in the inflorescence. Lacera comes from the Latin word lacerare, meaning torn or mangled, or "having irregular edges", in reference to the irregularly wavy-edged lip petal. Gracilis means graceful or slender. Author: The Field Museum From Flora of Indiana (1940) by Charles C. Deam This species is, no doubt, sparingly distributed throughout the state. In addition to the counties shown on the map it has been reported from Kosciusko, Noble, and Tippecanoe Counties. My specimens are from sandy or clayey soil in open, white and black oak woods and fallow fields and from sandy, black soil in a prairie habitat. [Deams says the following about S. beckii, a form of S. lacera var. gracilis in which the rachis is not twisted and stems bear a solitary subcylindrical root.] I have found this species in only two counties. It grew in hard, clay soil in open white and black oak woods. …… Indiana Coefficient of Conservatism: C = 3 Wetland Indicator Status: FAC |