Summer continues with monsoon winds, thundershowers and heat. What interests me the most is the increase in relative humidity. When we came to Colorado in 1965, the relative humidity averaged around 7 percent a day. Today it was 49 percent, and every day it is much higher than it was 50 years ago.
Why? Yes, we have had a wetter summer this year than most, but that doesn’t seem to me to be enough to account for the difference. I have read a report that shows the constant watering of lawns in Tucson, Ariz., has increased the relative humidity to such an extent that the flora of the desert for 10 miles east of Tucson is changing with new plants that require more moisture appearing every year. This is being documented by a local group and is a fascinating study.
I worked in my garden awhile this morning. The rains have surely made the weeds grow. While weeding, I noted the harebells I planted a few years ago are in full bloom. These are the native harebell, Campanula rotundifolia, which I started from seed and planted in my garden because they take little care, and are hardy and beautiful. They are also known as the Bluebells of Scotland. This is not because they only grow in Scotland. The name was given to them by British poets to differentiate between them and the Bluebells of England, which bloom much earlier in the spring and are a lily.
The scientific name, Campanula, comes from the Latin and Italian languages, and means little bell. Rotundifolia means round leaf and refers to the harebells’ round basal leaves. These basal leaves are interesting in that they appear on shoots from the roots and are seldom on the plant when it is in bloom. They are often on the young plant in spring and sometimes appear after the plant has bloomed and stay on the plant over winter. They then disappear.
The stem leaves are narrow strap shaped and like wire, as is the stem. In fact, the whole plant, stem, leaves and flowers are very dainty and do not look like they could survive in the places they grow. It is a circumpolar plant found all the way around the northern hemisphere. It is found all across Canada, Europe and Asia, dropping south in the mountains as it does in Colorado.
What the name “hare” means seems to be unknown. It is such a dainty plant. I can’t see how it could supply sufficient food or cover for hares.
There are a few other campanulas locally such as Campanula perryi, which used to grow in the valley below our house along Little Cub Creek, but it has been crowded out by smooth brome grass. It has a single, larger, bell-shaped flower at the top of each stem. There is also an alpine harebell, which grows above timberline. It is easily confused with the round leaf harebell, which is much dwarfed above timberline. Gardeners know the genus Campanula from such species as Canterbury bells, balloon flowers and other fine garden varieties.
Two other campanulas have become serious weeds. One is sometimes called creeping bell flower, Campanula rapunculoides, and the other is known as globe bellflower, Campanula glomerata. Both of these plants were introduced as garden plants, and they are very hard to control. The first looks much like our native, just coarser and rougher; the second has deep purple flowers and creeps everywhere. They came from Europe and should have been left there. I have both, and they have taken over my flowerbeds. They are just too easy to grow.
All the books say our native harebell blooms from June to September, but I often see ours still in bloom in October and even November.
If you haven’t been out birding because you think this is a dull time of year, the Denver Field Ornithologists have been seeing some good birds. They have reported a lot of interesting birds on the Rare Bird Alert. There were reports of arctic three-toed woodpeckers scattered around the state. If you are near any of the forest fire burns from the last year, give them a good look for these interesting birds. They seem to find food in the dead trees shortly after the burn.