Hesperis matronalis and the Importance of Latin Names

Admiring a lovely bouquet of flowers at the farmers' market and remarking that they are one my favorite spring flowers, I was told by the vendor that they "loved Phlox too". I bit my tongue. 
The flowers were Hesperis matronalis, commonly known as Dame's Rocket. Well, after doing a quick internet search I found they also go by: Damask violet, Dame's violet, Dames-wort, Dame's gillifower, Night-scented gilliflower, Queen's gilliflower, Rogue's gilliflower, Summer lilac (though it blooms in spring), Sweet rocket, Mother-of-the-evening, and Winter gilliflower (again, it blooms in spring). And therein lies the problem. Common names can never be relied upon to specifically identify a plant unless of course the Latin names become the common names in cases such as Clematis, Phlox, Astrantia, etc. And it's a point I always stress when giving gardening talks. Reputable nurseries deal only in Latin names, because the scientific binomial naming system only gives each plant one name--one, no more. It's a beautiful system, but being in Latin (or Greek) it tends to scare off the lay gardener and hence the profusion of common names and resultant confusion over exactly which plant is which.

A riparian stand of Hesperis matronalis

Hesperis matronalis is not a native American wildflower, though one might easily mistake it for one as it's so widespread. It's originally from Europe and the name 'Hesperis' is Greek for evening as the flowers are most fragrant later in the day. They are reliably biennial but in mild climates can become half-hardy perennials. They cling to moist areas of the landscape, and preferring shade, usually bridge the gap between the open field and woodland habitats. As a garden flower they're quite fleeting lasting only a couple weeks before the show is over for the season. I especially like their soft colors and sweet fragrance. It's worth saving a shady corner for them.

Of course, they do look remarkably like upright garden Phlox (Phlox paniculata) or Phlox divaricata (Woodland phlox) but can be easily distinguished by counting the petals: Hesperis has 4, Phlox has 5. Hesperis also blooms a little earlier in the season so overlap is rare.