Plant of the Week
Turpentine spring-parsley (Cymopterus terebinthinus)
By Walter Fertig
The celery family (Apiaceae or Umbelliferae) includes a number of edible (and poisonous) herbs that are often notable for their pleasant aromas. Among these are many of the spring-parsleys (genus Cymopterus) found over much of the desert and mountain country of western North America. Turpentine spring-parsley (C. terebinthinus) has an anise-like smell that emanates from its pulpy roots and fern-like foliage. This yellow-flowered species occurs from Washington to Montana south to California, Utah, and Colorado where it occupies rocky terrain of mountain foothills. Like other members of the parsley family, the flowers are arranged in umbrella-like clusters (themselves further clustered in larger umbrellas) forming a type of inflorescence called an umbel.
In many plant species, strongly aromatic foliage serves as a warning to potential herbivores that the stems and leaves are inedible. This might work to deter most insects, but apparently not the Anise swallowtail butterfly (Papilio zelicaon). Females of this species prefer to lay their eggs on Turpentine spring-parsley and another umbel that superficially resembles it called Gray's biscuitroot (Lomatium grayi). Anise swallowtail populations overlap with those of another close relative, the Oregon swallowtail (P. oregonius) in the mountains of southeastern Washington and northern Oregon, but each has adopted a different species upon which to lay its eggs (female P. oregonius butterflies prefer herbaceous sagebrush species). Researchers have discovered that the underlying cause of host plant preference in these butterflies is genetically based, rather than strictly behavioral. By subdividing their host plant preferences, two butterfly species can survive in an area where only one might otherwise be expected.
While butterflies are adept at identifying spring-parsleys, they can present a challenge to humans. About 45 species are recognized in the United States, most of which are distinguished by subtle flower and fruit characteristics. The genus name Cymopterus is literally translated from Greek for "wave wing" in reference to the mature fruits, which are relatively flat ovals except for raised papery or corky wings on the veins. These wings probably aid in spreading the fruits by the wind. The related genus Lomatium has similar fruits but lacks the raised wings. Several species of Cymopterus and Lomatium (often called biscuitroots) have edible starchy roots that were consumed by Native Americans. Since several umbel species (such as poison hemlock and water hemlock) are deadly poisonous, would-be wild gourmets with poor plant identification skills should exercise extreme caution.