Pollen Analysis Circular The last issue of the "Pollen and Spore Circular" (#18) was edited by Calvin J. Heusser and announced the fusion, indicating that "the spore and pollen section will constitute four to six pages in each issue and contain essentially the same material" as in the "Pollen and Spore Circular". The final issue also included abstracts from the First Palynology Conference (February 25, 1953), held at Yale University as well as correspondence from researchers working as far afield as Düsseldorf, Lucknow, and Indianapolis. It was in the pages of the "Pollen Analysis Circular" that the field of pollen analysis was given
Gum (botany) Gum (botany) Gum is a sap or other resinous material associated with certain species of the plant kingdom. This material is often polysaccharide-based and is most frequently associated with woody plants, particularly under the bark or as a seed coating. The polysaccharide material is typically of high molecular weight and most often highly hydrophilic or hydrocolloidal. Many gums occur as seed coatings for plant species; the adaptive purpose of some of these gummy coatings is to delay germination of certain flora seeds. An example of such a gummy coating occurs in the case of Western poison oak, a widespread shrub