Aquatic and Wetland Vascular Plants of the Northern Great Plains
25. Saxifragaceae, the Saxifrage Family
2. Parnassia L. -- Grass-of-Parnassus
2. Parnassia palustris L.
Plants with scapes 1.5-4 dm tall. Leaf blades ovate to subrotund, 1-3
cm long, broadly acute to obtuse or rounded at the tip, rounded to usually cordate
at the base, not decurrent on the petiole; bract-leaf usually cordate-clasping
on the scape. Sepals lanceolate to oblong-lanceolate, 4-11 mm long, herbaceous
throughout, 5- to 9-nerved, acute; petals ovate to elliptic-ovate, 8-15
mm long, usually 1.5-2X longer than the sepals, 7- to 11-nerved; staminodes
(7)9- to many-parted toward the dilated tip, 5-9 mm long. Jul--Sep. Calcareous
fens, shores, stream banks and wet meadows; occasional in e, c and nw ND and
n SD; (Circumboreal, in N.Amer. s to NY, MN, n SD, CO, NV and CA).