Cornus is a fascinating genus with species ranging from groundcover habits (Cornus canadensis) to large trees (Cornus controversa). I relate to students and garden visitors that if one dogwood is recognizable, then all can be. The leaves (primarily deciduous, several evergreen) are linear-ovate to ovate to broad ovate, margins entire (no teeth) with veins originating from the midvein and then turning toward the apex, almost paralleling the margin.  When the veins are and gingerly teased apart, rubbery strands are evident. Cornus alternifolia and C. controversahave alternately arranged leaves; all others opposite. Now the trick is to accurately identify the ~60 species.