If you are aging, and interested in honing your mental faculties, let me recommend this: move to a completely foreign ecosystem about 3,000 miles away from everything familiar and learn as many animals and plants as you can. Find a good library, check out an arm-load of field guides, and google until your computer starts to smoke. Forget crossword puzzles* and lumosity.com games. Get outdoors, and name every living thing in sight.
My latest naming exercise has been this beautiful grass - foxtail barley (Hordeum jubatum) - native to most of North America (except the Gulf states) and neighboring Siberia (from Bering Strait land-bridge days). I’ve never encountered it back east. It grows prolifically here in Coconino County.
It has a reputation for being weedy, growing where it is unwanted. When it is tender and new it is a useful forage grass, but once it matures and sets seeds it can be harmful to domestic grazers and wildlife. As seen in the bottom photo, the bristles on the ear of grain (called awns) are stiff and spiky enough to injure a grazing animal.
The awns also provide a distinctive means of seed dispersal. The structure works like a spindle, and the entire ear of grain rolls in the wind. A few days ago I was chased on a trail by several dozen seed heads that scurried underfoot as if they were alive.
* Of course I’m kidding about not doing crossword puzzles. What else are Sundays for? When God rested on the seventh day I’m sure it was so he could lounge about over a second cup of coffee with the Los Angeles and New York Times crosswords.