Adonis species: Pheasant's eye

Family

Ranunculaceae

Common Name

Pheasant's eye, Adonis, yellow ox-eye, flos adonis

Plant Description

The genus Adonis consists of at least 20 species of annuals and perennials originating primarily in Europe and cooler parts of Asia. Three introduced species are common in North America: Adonis aestivalis (red flower), A. annua (red flower with black center), A. amurensis (yellow flowers).

Closely related to the anemone and other members of the Buttercup (Ranunculus) family, Adonis are either annuals or perennials, arising from a tap root or rhizome, and with simple alternate finely divided pinnate leaves. Depending on the species, some Adonis grow up to 2 ft. and produce single solitary flowers terminally on the branches. Flowers have 5 - 8 greenish sepals and from 5 - 20 colorful petals, ranging in color from yellow to red, and occasionally white. Some species have a distinct black spot at the base of the petals (Fig. 19 and Fig. 20). Fruits are beaked globular achenes.

Figure 19. Adonis aestivalis.

Figure 20. Adonis amurensis.

All three of the species occurring in North America were originally introduced as garden plants which have escaped from cultivation. Adonis aestivalis in particular, has in some areas escaped to invade alfalfa fields and cause poisoning in horses fed hay containing the plant [1,2].

Toxic Principle and Mechanism of Action

Adonis species contain numerous cardenolides, including strophanthidin glycosides that are cardiotoxic [3]. Being a member of the Buttercup family, and considering that the clinical signs produced from eating Adonis are those of gastroenteritis, it is likely that the plants also contains ranunculin, which is hydrolyzed to the irritant protoanemonin once chewed and swallowed.

Risk Assessment

The Adonis species generally have a bitter taste and are not palatable. However as the species become popular garden plants, there is increased risk that household pets may be exposed to them. Adonis aestivalis has demonstrated that it can readily escaped from cultivation and become a problematic weed in hay feels thereby posing a risk to horses and other animals fed hay containing the plant.

Clinical Signs

The clinical signs of Adonis poisoning are primarily those of a gastroenteritis, resulting in vomiting and diarrhea. The diarrhea can be severe, causing dehydration and colic that will warrant appropriate supportive and symptomatic treatment. Myocardial necrosis can result in death in horses eating hay containing Adonis [2].