DACF Home → Bureaus & Programs → Maine Natural Areas Program → Communities, Plants, and Animals → Rare Plants → Isotria verticillata
Isotria verticillata (Muhl ex Willd.) Raf.
Large Whorled Pogonia
- State Rank: SX
- Global Rank: G5
- State Status: Possibly Extirpated
Habitat: Acid or mediacid mixed forests. [Hardwood to mixed forest (forest, upland)]
Range: Ontario to Massachusetts, Indiana, Michigan and Florida.
Aids to Identification: Orchids are recognized by parallel-veined leaves. Isotria verticillata and its close relative, I. medeoloides, are separated from all other orchids in Maine by their whorled leaves. Isotria verticillata is the larger of the two with stems commonly 20-40 cm tall and larger flower parts, including the 3.5-6.5 cm long slender sepals which are green-yellow in the basal portion and red-purple in the apical portion.
Ecological characteristics: Ecological relationships in Maine are not well known.
Phenology: Flowers in June.
Synonyms: Arethusa verticillata Muhl. ex Willd.; Pogonia verticillata (Muhl. ex Willd.) Nutt.
Known Distribution in Maine: This rare plant has been documented from a total of 3 town(s) in the following county(ies): Androscoggin, Oxford.
Reason(s) for rarity: Northern limit of range; conversion of forest lands in southern Maine.
Conservation considerations: Until the plant can be found again at its historic location or new locations, conservation considerations are moot.