June 28: 69, 37, 26, and 23 years ago

Some dogwoods for the dog days of summer
 
Who doesn’t love a good dogwood? Perhaps you are most familiar with flowering dogwood (Cornus florida), with the beautiful showy white flowers in woods and wooded roadsides across Pennsylvania in the spring.  Or perhaps, the commonly planted Japanese dogwood (Cornus kousa) from...you guessed it...East Asia.  But there are many different dogwood species, all in the genus Cornus.  Species in the genus are distributed across much of the temperate world in the Northern Hemisphere.  Rhoads & Block Plants of Pennsylvania list nine species found in the wild in our state.  They are trees or shrubs (with one exception). The veins on their leaves are quite distinctive, as is their bark and flower structures.
 
Why are these shrubs called dogwood?  There are several stories behind the unique common name. One is that the name was derived from the Celtic word “dag”, referring to its use of its nice wood as a dagger like tools or skewers. Another explanation is that the bard was once used as a treatment of mange for dogs.
 
Four dogwood species were collected on June 28 in Pennsylvania: 69,  37,  26, and 23  years ago:
 
Red-osier dogwood, Cornus sericea (aka Cornus stolonifera) June 28, 1950 in Erie County. Beautiful bright red stems.
 
Gray dogwood, Cornus racemosa June 28, 1982 in Blair County.
 
Cornus ammonum June 28, 1993 in Clarion County.
 
Cornus florida June 28, 1996.  White flowers from the spring are long gone.  (Well, the white structures aren’t actually petals, but modified leaves called bracts that surround a cluster of small yellowish flowers).
 
Over 2,600 dogwood (Cornus) specimens in the Carnegie Museum herbarium from across the world are available online, many with high resolution images: http://midatlanticherbaria.org/portal/collections/list.php?db=328&taxa=cornus&usethes=1&taxontype=2