This southeastern winter annual of lowland woods is easily overlooked or confused with Phacelia ranunculacea. It may occur in slightly damper (subhydric) places with slightly more acid soils, on average. Baskin et al. (1993) found that seeds of N. aphylla tend to germinate sooner than P. ranunculacea (mostly after 1-2 years in fall versus often 3+ years). In Ky. Nemophila is known mostly from bluffs and high terraces along the Mississippi Rv. in FULT and HICK. It may be more widespread in small remnants of suitable habitat than records suggest, being scattered across much of c. Tenn. (Ch) but still unknown in Ky. along the lower Tennessee Rv. or Cumberland Rv. It extends up the Ohio Rv. to s Ill. and perhaps HEND (M), but the latter coll. has not yet been located. There are also some recent records (2020) from the Green River watershed in the Big Barrens region (HART, LOGA, TODD), but to some extent these suggest adventive status. An old obscure record from LINC cannot be verified (Evans 1889). N. aphylla can be distinguished from P. ranunculacea as follows (W): flowers are solitary (versus 2-6 in cymes), and tend to be smaller (ca. 2-4 mm versus 3-5 mm) and paler (whitish versus pale blue-lavender); mature fruits are ovoid (versus globular with depressed apex), exceeding 2-4 mm calyx lobes (versus shorter than 5-8 mm lobes), unlobed (versus up to 4-lobed), and purplish (versus remaining green).