According to Cronquest (1988) the Lamiales "may be briefly characterized as Asteridae with a superior ovary consisting of 2 (-4) biovulate carpels with twice as many uniovulate locelli as carpels.  The fruit very often consists of 1-seeded, half-carpellary nutlets."  From the point of view of field identification, this group of three families is united by the common presence of a gynoecium that differs from those previously considered (Gentianales, Solanales, Scrophulariales) in that the number of ovules has been reduced to four and, via a 'derived' septum, each ovule occuplies its own locule:

1.  Leaves mostly alternate, flowers actinomorphic, stamens 5, stems terete, gynobasic style present.....  Boraginaceae

1.  Leaves mostly opposite, flowers zygomorphic, stamens less than 5, stems usually quadrangular:

            2.  Style terminal or nearly so, the ovary only shortly or not at all lobed at the top; plants seldom aromatic..... Verbenaceae

            2.  Style commonly gynobasic, uniting otherwise distinct lobes of the ovary; plant usually aromatic.....  Lamiaceae