I often reflect back on one of the few lines I’ve memorized from Romeo and Juliet; “A rose by any other name would smell as sweet.” No doubt that Shakespeare was talking about the common rose. But the common garden rose is in the genus Rosa, one of a hundred genera in the very large Rosaceae family that is even further sub-categorized into hundreds of different species and varieties.
Arborists are taught to learn about the taxonomical hierarchy of plants. This complex system of plant naming categorizes them into groups according to similarities and differences in their reproductive structures; from the most general to the most specific characteristics. You may recall the high school biology mnemonic device: King Phillip came over from great Spain. This represents the hierarchy: kingdom, phylum, class, order, family, genus, and species. In the landscape world, we deal mostly with genus and species, although plant families are also important. The diagrams below illustrate the complexity of taxonomy well beyond what I have simplified as well as the plants which fall into the Rosaceae family.
My arboreal brain makes the connection between the common rose and the Rosaceae family, more specifically at this time of year: the Pyrus or pear, one genus in the Rosaceae family. This tree is what prompted me to write this month’s blog. The Pyrus kawakamii, commonly known as the Flowering Pear or Evergreen Pear, is currently in its peak of glory. This observation is evident throughout our city of Santa Barbara due to its liberal planting. The flowering pear is a rose by a different name. It is quite beautiful at this time of year, but doesn’t smell sweet like the garden rose, nor does it live up to its rose compadre with its part time flower display. Obviously, Shakespeare was not referring to this rose family member.
For about two to three weeks per year the Flowering Pear is amazing. Similarly, for many rose family members, the flowering period is very short. This is also true for the stone fruits in the genus Prunus. Yet the pear’s enticement is enough to inspire people to plant it without concern for the other eleven months of problems.
I have regularly advised my clients and students that this tree is over-planted and over-rated. An assortment of leaf diseases are clearly visible on this tree species throughout most the year. The pear (or rose family member) is highly susceptible to bacterial fireblight and several fungal diseases that result in an abundance of distorted, declining, and dead leaves and stems.
It is important to acknowledge the good and bad points of a tree before selecting it for the landscape. With the pear, if a tree owner is only interested in the brief flowering period, than it may be the appropriate tree. If the foliage, shade, and low maintenance is the preference, then this is not the right tree, especially when its chosen to be the dominant species in the landscape. The aesthetic quality of a property dominated by one tree species, can be severely impacted when a pest or disease becomes established. For more information in selecting trees, please click on the link to a previous article where section one discusses choosing the right tree.
As far a Shakespeare’s perspective, if he were an arborist, he would have known that other plants in the rose family, may not smell as sweet.
How can I help you with your trees?