EHRETIACEAE (Ehretia Family)

Contributed by David J. Bogler and George Yatskievych

About 11 genera, 170 species, North America to South America, Caribbean Islands, Africa, Asia to Australia.

The Ehretiaceae have been treated as one of five subfamilies of the Boraginaceae by many botanists (Al-Shehbaz, 1991). Recent molecular work has suggested that the traditionally recognized family Hydrophyllaceae is nested within this group (Ferguson, 1998; Gottschling et al., 2001). One way of dealing with these data is to expand the definition of Boraginaceae to include the Hydrophyllaceae, as was advocated by the Angiosperm Phylogeny Group (1998, 2003), Judd et al. (2002), and Craven (2005). Arguing against this interpretation is that it creates a morphologically even more variable family that becomes accordingly more difficult to circumscribe in floristic manuals. Also, although the relationships among the subfamilies of Boraginaceae are still not fully understood, it is clear that the individual subgroups mostly are amply distinct based on both morphological and molecular data. Accordingly, Gottschling et al. (2001) and Diane et al. (2002) have taken the opposite approach and suggested the recognition of segregate families, with the Boraginaceae restricted to the mostly temperate herbaceous genera formerly included in the subfamily Boraginoideae. Although future research undoubtedly will result in further refinements of classification within the Boraginaceae complex, it seems most expedient in the present work to deviate from the system of Cronquist (1981, 1991) and to segregate the Ehretiaceae and Heliotropiaceae from the Boraginaceae and Hydrophyllaceae.

The Ehretiaceae are primarily a tropical and subtropical family of mostly shrubs and small trees. The family generally differs from the Boraginaceae in its less strongly lobed ovary with a more terminal, 2-branched style, fruits that often are drupelike, and seeds with abundant endosperm, as well as several more esoteric features. The sole Missouri representative is in a genus that is atypical for some of these features.