USDA lists five varieties while ITIS lists them all as Synonyms.
var. tenuifolia: only variety found in SC
Note slender, opposite, hairless, sessile, entire leaves with single vein down middle. five light blue/violet petals in a bell shape with slight ragged edges arising from generally each axil (stem-leaf joint) on a longer than normal pedicel (flower stem) with a white pistil extending to end of petals. The swollen flower buds are white and the interior of the corolla has dark purple spots. Plant is 12 inches tall, shrubby with slender grass like leaves.
Note there are many species within the Genus Agalinis that are very similar. A. tenuifolia is fairly common as it can exist in many types of habitats. The way to tell the difference is A. tenuifolia has a shorter corolla (more bell shaped) and a longer pedicel (flower stem), with darker green leaves.
It is classified as a semi- or partial parasitic plant in that the roots (haustoria), transfer food and energy for nearby host plants but it also has green leaves which photosynthesis.
SC Piedmont
TRAIL: Stevens Creek Preserve
HABITAT: open pine forest
ELEVATION: 80 m (260 ft)
BLOOM TIME: 28-SEP