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Date of Award


Document Type

Restricted Thesis: Campus only access

Degree Name

Bachelor of Arts



First Advisor

John Hayden


Euphorbia L. (Euphorbiaceae) is the third largest genus of flowering plants and consists of more than 2,300 species (Radcliffe-Smith, 2001). The genus has a worldwide distribution and can be found in almost all temperate and tropical regions (Radcliffe-Smith, 2001) and includes annual or perennial herbs, shrubs, cactoid succulents, and trees. Although very diverse, the genus has one common morphological characteristic which is the cyathium (Figure 1). The cyathium is a cup-shaped involucre that bears one or more glands on its rim and encloses multiple staminate flowers, each reduced to a single stamen, and a solitary pistillate flower found in the center. Cyathia often mimic bisexual flowers; appendages to the glands resemble petals, male flowers resemble stamens, and the centrally located pistillate flower easily could pass for the gynoecium portion of a flower. Some cyathia have numerous small bracts subtending the minute flowers within the involucre (Berry et al, 2017).