Thursday, October 18, 2012

Kidney-leaf Grass Of Parnassus (Parnassia asarifolia)

September 15th, 2012. We stopped by the spot on the highway through Black Rock Mountain State Park in Rabun County, Georgia, where we had found Parnassia asarifolia, the Kidney-leaved Grass of Parnassus, last year. We found them growing in a shaded seep/ditch on North Germany Mountain Road.

Last year, the road side mowers had left a swath of vegetation beside the seep that made it easy to sit and photograph the flowers. Unfortunately, this year the mowers had cut much closer to the edge of the ditch. The plants were blooming in the ditch itself.

A few of the flowers. The light green spots below the open blooms are buds

One of the buds beginning to open

The stamens of these flowers don’t develop at the same time. When the flower opens, the stamen are immature and lying against the ovary. In these photos, only one or two stamen have matured and opened away from the ovary; others are still aligned against the ovary with the immature anthers visible as a cream or light brown ovoid disks in the center of the flower. The circle of golden yellow spots are parts of sterile stamen-like organs (staminoids) that are thought to attract insects to the flower. There are five stamenoids; each has three ‘branches’ topped by the yellow structure.

A recently opened flower. The stamen are still immature and cream; one anther is starting to darken and will soon open out away from the center to release pollen

One of the anthers has matured and opened away from the center of the flower. Another anther is maturing and is just a little distance from the center. The remaining anthers are still immature (cream) or are starting to mature (light brown)

Two anthers have matured and opened away from the center. One anther is maturing, ready to open out, and two anthers are still immature (cream)

See an extensive set of photographs of these flowers here
Parnassia asarifolia is one of two species of Parnassia that grow in north Georgia; the other species is Parnassia grandiflora (Bigleaf Grass-of-Parnassus or Limeseep Parnassia). Parnassia asarifolia is known by the common names Kidneyleaf Grass of Parnassus, Kidney-leaved Grass-of-Parnassus, Appalachian Grass-of-Parnassus and Brook Parnassia.

Parnassia asarifolia is native to the United States and may be found in seeps from Virginia to Texas with the exception of Florida, Mississippi, and Louisiana. In Georgia, it has been reported from several counties in the Piedmont.
Click on an image to view a larger image
Identification resources:
Wildflowers of the Southeastern U. S.: Grass of Parnassus (Parnassia asarifolia) 
North Carolina Native Plant Society: Parnassia asarifolia (Kidney-leavedGrass-of-Parnassus, Appalachian Grass-of-Parnassus, Brook Parnassia)
United States Department of Agriculture Plants Database: Parnassia asarifolia (Kidneyleaf Grass of Parnassus)
University of North Carolina Herbarium: Parnassia asarifolia

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