Hypericum ascyron L.
Great St. John's-wort
Habitat: Moist rich soil, riverbanks. [Non-tidal rivershore (non-forested, seasonally wet); Forested wetland].
Range: Northern Maine to Manitoba, south to western New England, New Jersey, Ohio, Indiana, and Missouri.
Aids to Identification: As an herb in the St. John's-wort genus, H. ascyron displays the characteristic 5-petaled, yellow flowers and opposite, punctate leaves. It is unique within its group because of its large flowers (2.5-3.0 cm wide), large leaves (5-12 cm long), and 5-locular capsules.
Ecological characteristics: Very little is known about the ecological characteristics of this species in Maine.
Phenology: Flowers July - August.
Synonyms: Hypericum pyramidatum Ait.
Known Distribution in Maine: This rare plant has been documented from a total of 2 town(s) in the following county(ies): Aroostook.
Reason(s) for rarity: Disjunct from principal range.
Conservation considerations: The only known population in Maine occurs along a powerline right-of-way. It is unclear how maintenance of the powerline will affect the population.