Mid-May, p. 2

Bluet, Bedstraw family (Rubiaceae), Native

One sure sign of spring, in late April or early May, is the appearance of delicate bluets (Houstonia caerulea) in Westborough's lawns and in grassy places at the Reservoir. Patches of these tiny blue or blue-white flowers with yellow eyes add freshness to the new green of spring. They are pollinated by small bees and butterflies.

These small flowers come in two forms. A patch usually contains flowers of one form or the other. Each flower has both male and female parts, but in one form, the pollen-bearing male parts are tall while the pollen-receiving female parts are short. In the other form, the situation is reversed, with short pollen-bearing male parts and tall pollen-receiving female parts.

When pollinating insects rummage around in the flowers, pollen sticks to them in different patterns, depending on the height of the flowers' male parts. As the pollinators move to another patch of flowers, this patterning makes pollen from tall pollen-bearing parts available to flowers with tall pollen-receiving parts, and pollen from short pollen-bearing parts available to flowers with short pollen-receiving parts. This arrangement promotes cross-pollination and hinders self-pollination, leading to a healthier new generation of plants.

Northern White Violet, Violet family (Violaceae), Native

In May, when violets show up in lawns and gardens, northern white violets (Viola Pallens) nestle among grasses and dead leaves at the Reservoir. The five petals of this small, easily recognized flower are arranged conveniently for insect pollinators. The two upper petals and two side petals act as flags to attract insects, and the bottom petal gives them a place to land. The colored veins in the bottom petal lead insects toward the nectar that can be found in a spur at the back of the bottom petal.

Eastern Wild Columbine, Buttercup family (Ranunculaceae), Native At times, eastern wild columbine (Aquilegia canadensis) has appeared in the woods at the Reservoir, although it favors rocky cliffs and outcroppings. Its intricate, red-and-yellow blossom resembles a lantern and has long tube-like spurs that contain nectar. It is pollinated by bumblebees and hummingbirds, which can suck the nectar from the spurs. Other bees and wasps sometimes chew holes in the ends of the spurs to get at the nectar. This is the only wild columbine of the eastern United States, although about twenty other species--often with blue, white, or yellow flowers--grow in the west, especially in the Rocky Mountains. Most cultivated garden varieties of columbine are derived from a European species.

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