This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
About 15 species, natives of the north temperate and arctic zones. Besides the following, 6 or 7 others occur in northwestern America and one in Florida. Type species: Parnassia palustris L.
Petals sessile; leaves ovate, oval, orbicular or cordate.
Staminodia 3-5 at the base of each petal.
Flower 9"-i8" broad; petals much exceeding the calyx-lobes.
Staminodia not longer than the stamens, stout.
Staminodia longer than the stamens, slender.
Flower 4"-s" broad; petals equalling the calyx-lobes.
Staminodia 5-15 at the base of each petal, slender, united into a scale below.
Flower 1' broad; leaves cordate at base.
Flower 4" - 5" broad; leaves narrowed at base.
Petals clawed; leaves reniform; staminodia 3 at each petal, distinct.
Parnassia caroliniana Michx. Fl. Bor. Am. 1: 184. 1803.
Scape 6'-24' high, with a nearly sessile ovate clasping leaf below the middle. Basal leaves long-petioled, ovate, broadly oval or orbicular, obtuse at the apex, rounded or sometimes cordate at the base, or decurrent into the petiole, 1'-2' long; flower 9"-18" broad; calyx-lobes ovate-oblong, obtuse, much shorter than the sessile broadly oval white greenish-veined petals; staminodia generally 3 in each set, stout, distinct to the base, not longer than the stamens; capsule 4"-s" long.
Parnassia grandifolia DC. Prodr. 1: 320. 1824.
Similar to the preceding species, the scape bearing an ovate clasping leaf at the middle or much below it. Basal leaves as in P. caroliniana, but often larger and narrowed at the base; flower 1'-2' broad; calyx-lobes shorter than the sessile white petals; staminodia 3-5 in each set, slender or almost filiform, united only at the base, exceeding the anther-bearing stamens.
In moist soil, southwestern Virginia to Florida, Missouri and Louisiana. Ascends to 2200 ft. in Virginia. July-Sept.