Ballhead sandwort (Eremogone congesta) is a highly polymorphic species with, depending to the reference, somewhere between nine or eleven (or more) subspecies. Ballhead sandwort is a member of the Pink Family. Members of the Pink Family have five petals. However the plants I photographed along Lassen County (CA) Road 527, also called Ash Valley Road, had six petals. I was confused. Was this plant a ballhead sandwort or was I on the wrong path? Finally I found photographs of several E. congesta subspecies on Calflora that definitely had six petals. I believe this plant is Eremogone congesta ssp subcongesta.
Ballhead sandwort is a native perennial that arises from thick, spreading underground roots. The narrow, linear, opposite leaves are clustered at the base of the plant. The sparse cauline (stem) leaves are reduced in size. Atop the stem, which grows to about 12 inches in height, is a dense (sometimes open) inflorescence composed of up to as many as 50 flowers.
The flowers of ballhead sandwort have 5 greenish, ovate, papery sepals, which are often sharply pointed. The sepals are crossed lengthwise by 1 to 3 lighter green veins. The five (six) white petals have a notch at the top. There are 10 stamens with white filaments and pale yellow anthers. The anthers often become darker with age. The fruit is a capsule containing 4 to 8 red brown seeds.
Ballhead sandwort is found in the Rocky Mountain States and all states to the West (except New Mexico) from elevations of 4,500 to 12,000 feet. Its habitat is dry hillsides, plains, rocky outcrops and sagebrush flats.
Capitate sandwort is another common name for E. congesta. A synonym is Arenaria congesta.
The species name, congesta, refers to the crowded or congested flower head. Eremogone derives from the Greek words “erem” (lonely place or desert) and “gon” (seed). The alternate genus designation, Arenaria, comes from “aren”, the Latin for sand. This explains the common name sandwort – a wort is a plant.