Silly me, I posted this to the wrong blog. But since the previous post was also about seeds and nutrition, I guess it all works out.After puzzling over it for months (and happening to see
a related specimen in the medicinal garden at U-Dub), I can now report that the tall plants around the northern half of the garden are...
Salvia tiliifolia (Tarahumara chia, Lindenleaf sage).

I threw so many different seeds into those flanking beds in March and April, I couldn't be sure what was coming up until June. Since then, my best guess was that these plants were a
Monarda species, but they seemed too dark. When none of them flowered at the same time that I saw other plants in bloom around the area, I knew my best guess was wrong.
A closer look at the stems helped. They're rigidly square and I was reminded of the stems on
Salvia divinorum. This meant I was looking at a species in the
Lamiaceae, the mint family, of which I knew chia was a member.
Still, it took some time to find visual confirmation, because examples of other chia species are shorter or they produce flowerheads that I knew this plant wasn't going to make. A mention of
Tarahumara chia led me to Seeds of Change's website, where I found a matching photo. When I looked up that particular species, I found all of the matching descriptors.
Now, you might wonder, how did I not know what the plant would like if I broadcast its seed? That's because I used a packet of seeds from the spice section at
La Huerta supermarket in Geneva. Chia seeds, as discussed at length one other sites, have been used by our brothers and sisters in Mexico as a nutritive and sustaining food for centuries:

"Chia, is familiar to most of us as a seed used for the novelty of the Chia Pet™, clay animals with sprouted Chia seeds covering their bodies. Little is known, however, of the seeds' tremendous nutritional value and medicinal properties. For centuries this tiny little seed was used as a staple food by the Indians of the south west and Mexico. Known as the running food,
[Chia's] use as a high-energy endurance food has been recorded as far back as the ancient Aztecs.
"If you try mixing a spoonful of Chia in a glass of water and leaving it for approximately 30 minutes or so, when you return the glass will appear to contain not seeds or water, but an almost solid gelatin. This gel-forming reaction is due to the soluble fiber in the Chia. Research believe this same gel-forming phenomenon takes place in the stomach when food containing these gummy fibers, known as mucilages, are eaten. The gel that is formed in the stomach creates a physical barrier between carbohydrates and the digestive enzymes that break them down, thus slowing the conversion of carbohydrates into sugar.
"In addition to the obvious benefits for diabetics, this slowing in the conversion of carbohydrates into sugar offers the ability for creating endurance. Carbohydrates are the fuel for energy in our bodies. Prolonging their conversion into sugar stabilizes metabolic changes, diminishing the surges of highs and lows creating a longer duration in their fueling effects."