fen grass of Parnassus

not listed

NNR - Unranked

SNR - Unranked

not listed

OBL - Obligate wetland

OBL - Obligate wetland

OBL - Obligate wetland

Fen grass of Parnassus is a 8″ to 16″ tall, erect, perennial forb that rises from a short, thickened, underground stem (caudex) abd fibrous roots.

Basal leaves are on long leaf stalks and form a rosette. They are stiff, leathery, hairless, egg-shaped to almost circular, 1⅛″ to 2″ long, and ⅝″ to 1¾″ wide. They are always longer than wide. The base is broadly rounded or slightly heart-shaped. The blade extends down the leaf stalk a short distance below the point of attachment. The margins are untoothed.

A single, unbranched, hairless, 8″ to 16″ long flowering stalk (scape) rises from the rosette of basal leaves. There is usually a single leaf-like bract at or well below the middle of the stem. The bract is similar to the basal leaves only smaller. It is stalkless or on a short stalk, but does not clasp the stem.

The inflorescence is a single flower held erect at the end of the stem.

The flowers are ¾″ to 1½″ wide. Each flower has 5 green sepals and 5 white, ⅜″ to 11 ⁄16″ long petals with conspicuous, dark green veins. The 5 center veins of each petal are usually unbranched. There are 5 white stamens with brown anthers. There are also 5 white sterile stamens (staminodes) that are divided into 3 filaments for 3 ⁄5 or 4 ⁄5 of their length, each filament topped with an anther reduced to a gland. The staminodes are a little shorter than the stamens.

The fruit is a 4-valved, egg-shaped, 5 ⁄16″ to ½″ long capsule with numerous seeds.

8″ to 16″

White with dark green veins

Marsh grass of Parnassus (Parnassia palustris) has a larger bract, as large as the basal leaves. The bract clasps the stem. The staminodes are green or yellow, and are divided near the tip into 9 to 23 filaments.

Wet. Calcareous bogs, meadows, shores.

August to October

Sources

2, 3, 4, 5, 7, 28, 29, 30.

Native

Flower

Fruit