Staining Pollen Nuclei with Snows Alcoholic Hydrochloric Acid-Carmine

Nuclear staining of pollen grains is improved by using an alcoholic HCl-car-mine stain and Hoyer's mediem, a chloral hydrate-gum arabic mountant. This mountant completes differentiation of the pollen and clears cytoplasmic inclusions which may otherwise obscure the nuclei. Fixing anthers in 3:1 ethanol: acetic acid is recommended. Staining time at room temperature varies between 1 and 5 days, but can be shortened considerably by heat. Pollen is differentiated in 45% acetic acid-addition of Hoyer's medium makes the preparation permanent. The darkening of cytoplasm frequently found in acetocarmine slides does not occur. Pollen from carefullydried plants has given satisfactory staining and makes the method of geater use to taxonomists.