Helleborine. Epipactus helleborine.
Orchidaceae, the orchid family.

Plant: Erect stems to 30" with alternate, parallel-veined leaves, growing from fleshy, underground rhizomes, and bearing a long, terminal cluster of pink to green, bilateral flowers that have two lateral petals, and a lower lip (orchid-like). Perennial.
Flowers: Pink to green, 3/4"-1", with three pointed sepals, and three petals, two of which are pointed, the third forming a lip in classic orchid form. Flowers borne on a long, terminal cluster (raceme) along with small leaf-like bracts.
Leaves: Alternate, parallel-veined, ovate to narrowly ovate, to 4", declining in size going up the stem. Leaves have narrowly pointed tips, are smooth-margined, and sessile to clasping.
Fruit: A capsule, triangular in section, developing at the base of the flower.
Blooming: July-August
Habitat: Open woods, roadsides, meadows. Grows in an unusually broad variety of habitats.

Comments: Sometimes known as "weed orchid", this European import is invasive in parts of North America, where it grows in an wide variety of habitats. This is unusual for an orchid, many of which are specialized in narrow habitats and are protected.

Where to find it: I have found one small patch next to the fence separating the park from the highway on the south side of the pond.