A close-up of the flower of longstalk starwort from wet meadows around Tin Can Springs, Calamity Butte, Malheur National Forest.........July 18, 2010. Note the notched petals (cleft between 1/3-1/2 the length of the petals).
Longstalk starwort is a perennial wildflower with slender, mostly unbranched stems spreading or arising 15-40 cm long. The 4-angled stems as well as the leaves are glabrous and often shiny. The sessile leaves are linear to linear-lanceolate with acute tips. They are rigid and stiff with smooth margins, although the margins may be somewhat ciliate near their base. The branches of the inflorescence are much elongated (up 6-9 cm long) and subtended by short membranous bracts.
The inflorescence consists of a single flower to several flowers in a bracteate cyme. The sepals are lance-ovate in shape with acute tips (See photo at right.). They measure 4-6 mm long and are 3-nerved. The white petals range from one-half as long to over 50% longer than the sepals and are cleft about half their length.
Longstalk starwort may be found in damp meadows, on streambanks, and on moist rocky slopes from the foothills to alpine meadows in the mountains.
Also found in Eurasia, longstalk starwort may be found from Alaska south to California and south through the Rocky Mts. to New Mexico. It is found eastward to Newfoundland and south to Minnesota and New York.