Document Type

Thesis - University Access Only

Award Date


Degree Name

Master of Science (MS)

Department / School

Biology and Microbiology

First Advisor

Gerald A. Myers


Purple coneflower, Echinacea purpurea (L.) Moench, portrays various medicinal properties including immunostimulatory effects. These medicinal qualities have been attributed to an isobutylamide named echinacein. Echinacea plants contain a network of oleoresin canals throughout the roots, floral buds, and seed achenes. This project involved a study of the development of oleoresin canals in the receptacles of buds of various stages of growth. Quantification of microscopic features was accomplished through the use of stereological methods. A semi-automatic image analysis system was utilized to obtain areal measurements of canal and receptacle areas. All data were analyzed with SAS, a computerized statistical analysis program. The canal area to receptacle area ratio was analyzed and a regression line indicated a direct relationship up to the maximum observed canal area. An inverse relationship was apparent in the oldest stage of growth. Analysis of floret development indicated a steady increase in canal volume during early stages of floret differentiation. At the time of pollen grain maturation, receptacle size increased significantly but canal volume leveled off. For maximum active substance per mass of tissue, harvest should occur when the most buds are in the microspore developmental stage, receptacle diameter 6.0mm - 7.0mm.

Library of Congress Subject Headings

Oleoresins -- Analysis
Echinacea (Plants) -- Therapeutic use
Herbs -- Therapeutic use




South Dakota State University



Rights Statement

In Copyright