pollen grain

noun

Updated on: 18 May 2018

Definition of pollen grain

: one of the granular microspores that occur in pollen and give rise to the male gametophyte of a seed plant

Recent Examples of pollen grain from the Web

For example, a single corn plant produces 2 [million] to 5 million pollen grains, and an ear of corn has a few hundred seeds.

— brigit katz, Smithsonian, "Watch This Pine Tree Unleash a Huge, Fluffy Pollen Cloud," 10 May 2018
The peptides are the molecular signal that triggers the body’s immune system, so more peptides on a given pollen grain increases the severity of the allergy.

— umair irfan, Vox, "It’s not your imagination. Allergy season gets worse every year.," 28 Apr. 2018
In 2000, there were about 8,000 pollen grains per meter cubed.

— CBS News, "How climate change is making allergy season worse," 20 Apr. 2018
Bigelow has pulled cores from the bottom of lakes in Western Alaska to find pollen grains and bits of ancient plants.

— ned rozell, Anchorage Daily News, "Was the Bering Land Bridge a good place to live?," 24 Feb. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'pollen grain.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.