Key to the genera of Boraginaceae

1Style terminal on top of the undivided or divided fruit
1'Style basal between the 4 or rarely fewer separate nutlets. Herbs
2Fruits 2, laterally compressed capsules with a wide wing, bilocular, with one larger erect and one smaller pendent ovule
2'Fruit drupaceous or separating into 4 unilocular nutlets or two 2-locular mericarps, or undivided, hard
3Style once or twice forked, with or without a distinct stigma, sometimes undivided with 2 stigmata. Fruit drupaceous with 1 to 4 pyrenes and 4 seeds
3'Style simple or forked, surrounded by an annular stigma. Fruit drupaceous or separating into 4 nutlets or 2 mericarps
4Style twice forked. Fruit with a single 4-locular pyrene. Trees, shrubs or woody climbers
4'Style simply forked or styles 2. Fruit with two 2-seeded or four 1-seeded pyrenes or remaining entire
5Creeping herb
5'Trees, shrubs or climbers
6Fruit breaking up into two 2-seeded pyrenes. Style forked
6'Fruit breaking up into four 1-seeded pyrenes or endocarp remaining entire
7Style undivided, with 4 capitate stigmata. Fruit breaking up into four 1-seeded py- renes. Flowers in a loose, scorpioid inflorescence
7'Style forked to below middle, stigmata indistinct. Endocarp of fruit remaining en- tire with 4 seeds. Flowers single or a few in fascicles
8Fruit drupaceous. Pericarp corky or fleshy. Trees, shrubs or climbers (in Malesia)
8'Fruit separating into 4 nutlets or two 2-seeded mericarps, rarely undivided with mostly 1 locule by abortion
9Anthers with long, twisted awns. Fruit separating into nutlets only at a late stage
9'Anthers without awns. Fruits with 4 separate locules already at an early stage
10Nutlets perfectly smooth
10'Nutlets warty, with spines, tubercles or glochids
11Nutlets with a ventral keel or angle and a shortly stipitate basal, horizontal areola
11'Nutlets without a ventral keel or angle. Areola minute, oblique, not stipitate
12Filaments with an erect appendix; anthers forming a column, usually subacute. Nutlets with a basal areola surrounded by a thick, tumidulous margin; gynobasis flat
12'Filaments without an appendix; anthers not forming a column, obtuse. Nutlets with a sub ventral areola, gynobasis short conical to pyramidate
13Nutlets without glochids
13'Nutlets flat to convex dorsally, not cup-shaped, with glochids at least marginally and on ventral side
14Nutlets concave dorsally, much larger than 1 mm
14'Nutlets ellipsoidal, scarcely larger than 1 mm
15Narrowly pyramidate stylar column present between the nutlets
15'Stylar column absent between the nutlets that are inserted on a flat disc