Isotria

Rafinesque

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

Common names: Whorled pogonia orchid
Etymology: Greek iso, equal, and tri, 3 probably referring to 3 sepals of equal size and shape
Treatment appears in FNA Volume 26. Treatment on page 511. Mentioned on page 496.
 TaxonIllustrator 
FNA26 Plate 082.jpegIsotria verticillata
Pogonia ophioglossoides
Goodyera oblongifolia
Goodyera repens
Barbara Alongi
Barbara Alongi
Barbara Alongi
Barbara Alongi

Herbs, perennial, terrestrial, winter dormant. Roots long, slender, hairy with mycorrhizae. Stems simple, hollow, fleshy, smooth, glaucous. Leaves (2–) 5 (–6), appearing whorled. Inflorescences terminal; bracts absent. Flowers 1–2, resupinate, erect, yellowish green to white, yellow, and purple, subsessile to pedicellate; sepals of same color, linear-oblanceolate to lanceolate, of equal size; petals oblanceolate, elliptic-obovate, or elliptic-lanceolate, enclosing column; lip apically 3-lobed, lateral lobes triangular, margins involute; callus forming fleshy medial crest; column white, apex denticulate; anther operculate; pollinia 2, hinged, soft, mealy; rostellum obscure; pollen in tetrads, granular; ovary green, slender. Fruits capsules, commonly persistent through following growing season, erect, ellipsoid-cylindric, dehiscent in fall. Seeds 1.2 × 0.2 mm. x = 9.

Distribution

e North America

Discussion

Species 2 (2 in the flora).

Selected References

None.

Key

1 Sepals green to light green, less than 30 mm; lip light yellowish green to pale greenish white, streaked with green; pedicel of mature capsule 5–17(–20) mm; stem and leaves pale grayish green. Isotria medeoloides
1 Sepals purplish brown, greater than 30 mm; lip yellowish green to white, streaked with purple; pedicel of mature capsule 20–55 mm; stem purplish to brownish green; leaves green to dark green. Isotria verticillata
... more about "Isotria"
self-pollination +
denticulate +
Loyal A. Mehrhoff +  and Michael A. Homoya +
Rafinesque +
indehiscent +
not +  and articulate +
conduplicate +  and plicate +
flattened +, triangular +  and cylindric +
Whorled pogonia orchid +
e North America +
Greek iso, equal, and tri, 3 +  and probably referring to 3 sepals of equal size and shape +
subsessile +  and pedicellate +
yellow +, yellowish green +  and white +
erect +  and resupinate +
ellipsoid-cylindric +
lateral +  and terminal +
petiolate +, sessile +  and simple +
cauline +  and basal +
reduced +
3-lobed +
larger +
differing in form and color +
slender +
1-many-flowered +  and cymose +
pendent +  and erect +
elliptic-lanceolate;elliptic-obovate;elliptic-lanceolate;elliptic-obovate;oblanceolate +
Med. Repos., hexade +
aerial +  and subterranean +
slender +
1.2 cm12 mm <br />0.012 m <br /> (?) +
minute +
0.2 cm2 mm <br />0.002 m <br /> (?) +
free +, distinct +, adnate +  and connate +
linear-oblanceolate +  and lanceolate +
foliaceous +
not +  and alike +
hollow +  and simple +
pendent +  and erect +
proliferous +
thickened +  and stout +
concave +  and convex +
Isotria +
Orchidaceae (tribe Vanilleae) subtribe Pogoniinae +
aquatic +, lithophytic +, terrestrial +  and epiphytic +
saprophytic +, photosynthetic +  and mycotrophic +