Isotria verticillata

(Muhlenberg ex Willdenow) Rafinesque

Med. Repos., hexade 2, 5: 357. 1808

Common names: Large whorled pogonia orchid
IllustratedEndemic
Basionyms: Arethusa verticillata Muhlenberg ex Willdenow Sp. Pl. 4(1): 81. 1805
Synonyms: Pogonia verticillata (Muhlenberg ex Willdenow) Nuttall
Treatment appears in FNA Volume 26. Treatment on page 512. Mentioned on page 151, 513.

Herbs, clonal, rhizomatous, 4–40 cm. Stems purplish to brownish green, glaucous; scales 2–4, typically below soil line, purplish. Leaves green adaxially; blade oblong-lanceolate, obovate, or elliptic, 25–100 × 10–53 mm, apex obtuse to acuminate, sometimes glaucous abaxially. Flowers pedunculate, showy, sweetly fragrant, without nectar; sepals spreading, purplish brown, narrowly lanceolate, 34–67 × 2–4 mm; petals yellowish green, elliptic-obovate to elliptic-lanceolate, 15–25 × 3–7 mm; lip yellowish green to white, streaked with purple, oblong, 15–25 × 8–9 mm, lateral lobes streaked with purple, margins involute, middle lobe rounded, margins revolute, undulate; callus green, longitudinal, fleshy; column 8–12 mm; ovary 20–30 mm; rostellar flap prominent. Capsules 20–42 × 5–10 mm; pedicel of mature capsule elongating to 20–55 mm. 2n = 18.


Phenology: Flowering Apr–Jun.
Habitat: Acidic soils, in dry to mesic forests, seeps, sphagnum bogs
Elevation: 10–2000 m

Distribution

V26 1045-distribution-map.jpg

Ont., Ala., Ark., Conn., Del., Fla., Ga., Ill., Ind., Ky., La., Maine, Md., Mass., Mich., Miss., Mo., N.H., N.J., N.Y., N.C., Ohio, Okla., Pa., R.I., S.C., Tenn., Tex., Vt., Va., W.Va.

Discussion

Isotria verticillata frequently forms extensive clones with hundreds of stems. It is pollinated by solitary bees of the Andrenidae, Anthophoridae, and Halictidae; plants are apparently self-compatible (L. A. Mehrhoff 1983). Nonflowering plants only rarely have a white, arrested floral bud (1–2 mm).

Selected References

None.

Lower Taxa

None.

... more about "Isotria verticillata"
Loyal A. Mehrhoff +  and Michael A. Homoya +
(Muhlenberg ex Willdenow) Rafinesque +
Arethusa verticillata +
Large whorled pogonia orchid +
Ont. +, Ala. +, Ark. +, Conn. +, Del. +, Fla. +, Ga. +, Ill. +, Ind. +, Ky. +, La. +, Maine +, Md. +, Mass. +, Mich. +, Miss. +, Mo. +, N.H. +, N.J. +, N.Y. +, N.C. +, Ohio +, Okla. +, Pa. +, R.I. +, S.C. +, Tenn. +, Tex. +, Vt. +, Va. +  and W.Va. +
10–2000 m +
Acidic soils, in dry to mesic forests, seeps, sphagnum bogs +
Flowering Apr–Jun. +
Med. Repos., hexade +
Illustrated +  and Endemic +
Pogonia verticillata +
Isotria verticillata +
species +