I was never of fan of 70’s rock – either during the 70’s or now – but I could not resist borrowing a Deep Purple line for this blog title. It fit so well and like, man, it is a groovy thing when art meets nature. Smoky yellow clouds of tree pollen are landing on the still marsh waters and creating wonderful swirled patterns on the surface. There is smoke on the water and in the air.
This is a good time of year to think about tree pollen because it is everywhere. Not all of it is bad for you but a good part of it (that is, the part that isn’t landing on the water) is travelling into your nostrils and travelling deep into your head. It originates from numerous forms of tiny tree flowers, but most of the smoky water coating pollen comes from two wetland loving trees – Black Alder and Cottonwood.
Both of these trees produce their flowers on catkins. They are prompted by the warmth of spring to open up, expose their flowers, and shed their pollen. It is a form of “letting one’s hair down” I suppose. Only the male flowers produce pollen, so if you are in a sneezy mood you need to place blame on the masculine side of the picture.
It is easy to tell the boy from the girl flowers on a Cottonwood tree because the boys wear red dangling ear-rings (above) and the females wear green ones that eventually turn to fluff. This is a horribly simplified view of things, but as a horribly simple person I find no problem with a statement like that. Cottonwood trees are either male or female (“He said/She said” plants or “diecious” if you are a stickler for term accuracy). The male trees are now holding out their reddish catkins for the world to see. They are shedding cascades of tiny pollen grains into the air.
Cottonwood pollen grains are perfectly round and have a crackled surface. They look like Jovian moons when viewed under high magnification. On the water surface they look like yellow smoke, but you already know that.
The larger portion of that yellow water smoke, however, is contributed by the Black Alder trees. Immigrants to our neck of the woods, these trees are among the first pollen shedders in our area. Both the male and female flowers are found on the same tree (“He-she trees” or “monecious” if you are a stickler for term accuracy). The dangling pollen-shedding catkins (see below) are male while the delicate feminine flowers are encased within cone-like structures.
Alders are world class pollen shedders because they produce so many flowers. In one study, it was determined that an average Black Alder produced some 7,300 catkins per tree. Each catkin had an average of 580 flowers in it. That makes for around a gazillion flowers per tree (rounded off, of course). Each catkin produces over 19,500,000 pollen grains. The catkins are so pollen-laden that even after they fall from the tree they still leave worm-like pollen marks on the ground (see below).
Alder pollen grains are slightly smaller than Cottonwood grains buy a few micrometers (a micrometer is 1×10−6 of a meter or “super eensy-weensy” if you are still insisting on technical talk). These grains look like stuffed Ravioli pasta with dimples at each corner (most have four dimples, while others have five or six). Perhaps the most telling of Alder facts is the estimated pollen poundage per tree. Based on that same afore-mentioned study each tree can produce an average of 884 grams of pollen per season. That’s nearly two pounds of pollen dumped into the wind per tree per season.
Although I couldn’t track down the pollen figures as they relate to the Cottonwood, you can safely imagine that we are also talking in terms of poundage per tree. That means lots of smoke on the water and lots of itchy eyes, wheezing, and dripping humans. For allergy sufferers this excess love dust is like “fire in the sky.”
NOTE: I don’t show you any images of pollen grains, but can refer you to the sculpture work of Jo Golesworthy to get an idea of what they look like. This artist produces giant pollen sculptures that any hay fever sufferer would love to have in their garden.