Related Experiment Video
Updated: Jun 22, 2026

Visualization of Leaf and Bracteal Nectaries of Cotton using Digital Microscopy to Improve Scoring Accuracy and Data Preservation
Published on: February 6, 2026
The timing of nectar secretion in staminal and staminodial glands in Lauraceae
1Universität Hamburg, Biozentrum Klein Flottbek und Botanischer Garten, Hamburg, Germany. rohwer@botanik.uni-hamburg.de
Abstract:
The flowers of many Lauraceae have two kinds of glandular organ: paired glands at the base of the filaments of the third androecial whorl, and staminodes with a glandular head, corresponding to a fourth, sterile androecial whorl. So far, it is unknown why there are two different kinds of organ with apparently the same function. Observations now show that the staminal and the staminodial glands secrete nectar at different times in the heterodichogamous flowering cycle, and are therefore essential for the pollination of bisexual Lauraceae flowers.
Related Concept Videos
Regulation of Transpiration by Stomata
Pollination and Flower Structure
Exocrine Glands: Methods of Secretion
Merocrine Secretion
Merocrine secretion is the most common type of exocrine secretion. The secretions are enclosed in vesicles and moved to the cell's apical surface, where the contents are released by exocytosis. For example, mucous, a watery secretion rich in the glycoprotein mucin, is a merocrine secretion. The eccrine glands...
Biological Clocks and Seasonal Responses
Introduction to Seed Plants
Morphogenesis

