A Rose Is a Rose, Is an Apple, Is a Berry
Botanically speaking, roses belong to the Rosaceae (ro-ZAY-cee-ee) family. This is a huge family, encompassing over 2800 species of plants, including fruit trees, shrubs, berries and, of course, roses.
There isn't a single set of characteristics you can use to identify all members of this family, but there is one identifier that several genera share: a star-like shape at the base of the fruit.
Here you see cotoneaster berries with those distinctive "stars" on the bottom.
Once you know to look for this characteristic, you will begin to recognize other relatives in this family. These include: Hawthorn, Pears, Rowan, Cotoneaster and Pyracantha.
Fall is the best time of year for this, of course, because that's the season when these fruits are ripe.
Here you see the "star" at the base of an apple, another rose relative. You'll find stars on the bottoms of pears, too.
And notice the stars on rose "hips" this time of year.
(Pictured here are Rosa glauca hips.)
Beyond this bit of botanical trivia, it is useful for gardeners to be aware of these family relationships. Many members of the Rosaceae family share a susceptibility to fungal diseases, such as black spot on roses and scab on apples. Knowing this, a gardener can be prepared to take steps to keep plants healthy, which might include the use of dormant oil sprays, good sanitation practices and companion planting with members of the allium family (garlic, chives, onion, etc.)
So there's your mini botany lesson for today. Now go out and do your own version of "star search."