Someone noted that Osage orange is sometimes hyphenated. Some plant
writers have stipulated that osage-orange be hyphenated because it is
not a true orange species like the sweet orange.

http://www.ars-grin.gov/~sbmljw/introd.htm#common

However, this hyphenation rule is probably broken more often than it
is followed. The USDA Plants database http://plants.usda.gov/ uses
Osage orange. Even dictionaries use Osage orange:
http://dictionary.reference.com/search?q=osage%20orange

There are many hundreds, if not thousands of common plant names that
would need to be hyphenated to follow this rule, including
hedge-apple, sugar-beet, Douglas-fir, Wollemi-pine, dawn-redwood,
golden-Vietnamese-cypress, giant-sequoia, tulip-poplar, umbrella-pine,
incense-cedar, Norfolk-Island-pine, bald-cypress, red-cedar,
golden-larch, Kentucky-coffee-tree, black-locust, honey-locust,
mock-orange, Oregon-grape-holly, mountain-laurel, Swedish-ivy,
silk-oak, poison-oak, Jerusalem-oak, she-oak, African-oak,
Jerusalem-artichoke, poison-ivy, Japanese-ivy, Boston-ivy, German-ivy,
ground-ivy, castor-bean, asparagus-fern, screw-pine, ground-pine,
strawberry-geranium, African-violet, rock-rose, moss-rose,
club-moss, bell-pepper, sweet-potato, milk-vetch, Jerusalem-cherry,
lily-of-the-valley, water-lily, pond-lily, sego-lily, etc.

To make matters more complex, they want to have exceptions, such as
sugarbeet.

However, ultimately the rule is silly for several reasons including
the following:

1. Common names are not scientific nor officially regulated by plant
taxonomists.

2. Scientific names are needed for accuracy so a common name alone is
insufficient for most publications.

3. There is no method to mark the difference between hyphenated and
unhyphenated versions when speaking.

4. There are many single-word common names that are misapplied such as
geranium for Pelargonium species, peanut, mayapple, mimosa, etc.

5. It would require a large and cumbersome code of nomenclature for
common plant names to officially assign each common name, such as
locust and hemlock, to one genus, family or phylum and to list the
many exceptions to the hyphenation rule.


David R. Hershey