I’m Pollen For You
It’s a lot prettier when it’s on paper rather than launching your sinuses into full revolt and unleashing a Niagara Falls-level torrent of snotty discomfort, eh?
Pollen is strange stuff. Although many pollen grains are only a few millionths of a meter across, plants sculpt remarkably intricate and diverse suits of armor for these mobile gametes, having evolved a remarkable variation of symmetries.
To deliver a plant’s male genetic material to female plant parts, it’s got to be both sticky and tough. Within the pollen grain, a dormant cell lies poised for division, ready to burrow a pollen tube toward the seed ovum when it finds the right female parts. Surrounding that hibernating genetic material are two layers of protection: cellulose-rich intine and sporopollenin-sculpted exine.
So tough are those outer layers, so effectively do they protect the cells within, that pollen grains can be used to study everything from crime scenes to ancient climates. The spores below have survived more than 400 million years, dating from a time when plants had just invaded land and begun to reach up toward the sun:
Illustrations up top are from Ueber de Pollen, by Carl Julius Fritzsche (1837). If you speak German, there’s more small wonder for you here.
(via Public Domain Review)