Mapping here remains somewhat tentative. This species ranges from Central America to southeastern states, where it occurs mostly in thin pine woods or savannas on damp sandy soils of the Coastal Plain. S. ciliata is close to the more widespread pauciflora. These two species have often been confused or combined, but they have been distinguished in recent treatments (FNA 23, W). Based on recent analysis, T. Smith (pers. comm.) has found these taxa to be weakly separated at best. S. ciliata has 3 tubercles at the base (hypogynium) of the achenes, but these are often lobed; in pauciflora, there are 6 paired but distinct tubercules. Also, the achenes of ciliata are usually longer (2-3.5 mm versus 1-2.5 mm), and leaves are often relatively wide (1-7 mm versus 1-2.5 mm). Colls. from MCRE (KY, MO, US) and TRIG (KNK) have been identified as ciliata with some certainty, but the others should be rechecked; see KSNPC for recent reports. S. ciliata was not mapped in Ky. by FNA 23, and it may be unknown across n. Tenn. (Ch).