Along with the coming of July, we see summer happening in the region. Bird babies have become fledglings and these youngsters have moved on from their nests. Butterfly, moth and dragonfly species are more diverse and abundant now.
The first cicadas call in the daytime while crickets chirp in the warm nights illuminated by fireflies. A few berries and mushrooms have appeared and July wild flowers replace the waning ones of June.
Now in the fields, meadows and roadsides, we see newly open buds of milkweeds, fireweeds, thistles, black-eyed susans, early goldenrods and the unique evening primroses.
Several plants are named for the time of day in which they bloom. We are most likely familiar with morning glories that open their delightful horn-shaped flowers in the forenoon or the four o'clock that blossoms later in the day. Many others, without such labels, also respond to light available at certain times. Hawkweeds, dandelions, daisies and day lilies all open and close in a daily ritual.
Nearly all of these common plants choose the brighter times of the 24 hour period. But not so with the evening primroses.
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Growing robustly to about four feet tall, the evening primrose will open its flowers any time from 4 p.m. to 10 p.m. Sometimes, the opening is rapid and a close observer can see it happening. Flowers are on top of the leafy stalk.
Blossoms are large, about two inches across, and with four petals. This petal number is uncommon among local flora and so we are not likely to confuse evening primrose with any other plant now blooming in the Northland.
The petals that open at dusk often remain that way until the following dawn. It is not unusual to see these yellow blossoms in the a.m. still partially open from the previous night. Day-flowering plants use colors along with fragrance to entice the passing butterflies and bees to stop by.
Evening primrose needs to rely on the latter to bring in nocturnal fliers -- the moths. Moths are quick to congregate around the aromatic flowers and some even decide to stay.
Occasionally, a visit to these plants in the morning will reveal a moth that gathered nectar last night and decided to stay for the day. Perhaps it wants to be the first in line for the next twilight performance.
Evening primroses differ from most of our plants in another way too. They are biennials. Growth of the first year is limited to a sprawling on the ground. Known as a rosette, this flat arrangement of green and reddish leaves is how it spent last winter. This spring, during its second year of life, it quickly grew to this summer height that we now see. Some flowers will linger into September, but for the most part, evening primroses are part of the Northland's warmer nights when moths fly.
These gentle and cooling evenings of July are made more pleasant by the opening of this nocturnal flower that often opens its four yellow petals near our homes.
Larry Weber is author of the "Backyard Almanac" and "Butterflies of the Northwoods." He lives in Carlton County and teaches natural science at Duluth's Marshall School.
