Wild Columbine (Aquilegia canadensis) is in full flower, and its design and color beckon to a recently-returned migrant that is attracted to red as well as tubular flowers – the Ruby-throated Hummingbird. Not only does the flowering of Wild Columbine coincide with the arrival of hummingbirds in May, but the ranges of these two species are much the same. Wild Columbine’s five petals are in the shape of spurs, the tips of which contain nectar. Only hummingbirds and long-tongued bees can reach the nectar, and thus are its primary pollinators (there is a short-tongued bumblebee that tears open the tip of the spur in order to reach the nectar). While the hummingbird hovers beneath the flower and drinks nectar, its head rubs against Columbine’s long anthers, and the resulting pollen on the hummingbird’s head is brushed off onto the long styles of the next (Columbine) flower it visits, thereby pollinating it.
Early saxifrage (Micranthes virginiensis) is well named – it flowers early in the spring, and is often found growing in or on rocks. (The name saxifrage derives from the Latin words “saxum” meaning rock and “frangere,” to break. When the small seeds of saxifrage lodge in rock crevices and germinate, the plant looks as though it split the rock.) If you look closely you’ll see that early saxifrage’s flower stalk has many hairs – they are glandular and their stickiness is thought to deter ants from taking nectar from the flowers, so that it can attract more efficient pollinators.
Hepatica has finally opened its hairy buds and greeted the world with its beautiful white, pink, blue and lavender blossoms. Typically the only wildflowers to appear earlier than this member of the Buttercup family are skunk cabbage and coltsfoot. Like many flowers, hepatica blossoms open on sunny days, and close at night and on cloudy days. This prevents rain from washing out the pollen and nectar which help attract pollinating insects, including early-flying bees and flies.
Bumblebees are nothing if not perseverant. Prying Bottle Gentian’s (Gentiana andrewsii) petals open is a monumental task, and one that few insects, other than large species of bumblebees, attempt — much less accomplish. The relationship of bumblebees and Bottle Gentian is an example of a mutualistic association — the bees benefit by having exclusive access to a bountiful and sugary nectar supply, and the plants benefit by attracting “loyal” pollinators that improve the chances for cross pollination.
Of all the insects I’ve found in milkweed patches over the years, the Hummingbird Clearwing is one of my favorites. It is a species of sphinx moth, named for its habit of hovering at flowers while it gathers nectar with its proboscis in a manner similar to that of hummingbirds. In fact, they are often mistaken for hummingbirds. The transparent wings, light brown thorax and dark chestnut abdomen are the field marks to look for. A diurnal moth, the Hummingbird Clearwing can often be found during the day in milkweed patches.
It’s easy to miss Blue-eyed Grass (Sisyrinchium angustifolium), as its flower is only about ½” in diameter and the plant only reaches a height of six to twelve inches. Blue-eyed Grass is a member of the Iris family, not, as its name implies, a member of the Grass family, although it does have stiff, grass-like leaves. Dark lines on its petals and sepals may well serve as nectar guides, leading pollinators to the yellow center. Each blossom is open for only a day at most. Typically you find Blue-eyed grass growing in sunny, wet fields, often on elevated soil — Thoreau noted that if you followed Blue-eyed Grass through a wet meadow,
you could keep your feet dry.
Fringed Polygala (Polygala paucifolia) looks a bit like a miniature orchid, but it is not — it is in the Milkwort family. The structure of its ¾-inch bright magenta-pink blossoms is well-suited for its bumblebee pollinators. The bee lands on the pink fringe at the front of the flower and its weight triggers the white “keel” to drop down. A slit at the keel’s top opens, exposing the reproductive parts of the flower. Pollen from the stamens is rubbed onto the bee’s hairs while it probes deeply into the base of the flower for nectar, while pollen from a previously visited Fringed Polygala is scraped off onto the stigma, where it needs to be in order for fertilization to take place.
If you find a blossoming Trout Lily in the woods it is quite likely that you will also find one of its most common pollinators, the Red-necked False Blister Beetle (Asclera ruficollis), on it. Ardent pollen eaters, this group of beetles obtain their common name because many species cause blisters when pinched or squashed against skin. Adults mate on flower heads during pollen feeding. Both sexes feed on pollen, which acts as an attractant, but the female will not accept the male until her gut is packed full of pollen. She stores the pollen in a special intestinal sack in which an enzyme causes the pollen to partially germinate — this causes the indigestible covering of the pollen grain to rupture. She then digests the contents of the pollen grain, which she uses to manufacture eggs.
Spring Beauty (Claytonia virginica) is one of our earliest woodland wildflowers to blossom, and thus an important source of nectar and pollen for the earliest foraging insects. Pink lines (“bee guides”) on each of its five petals lead pollinators to the center of the flower, where the nectar is located. The pollinator in this image, Andrena erigeniae, is one of the more common species of bees that visits Spring Beauty in the early spring. Notice the slightly pink pollen she has gathered into the pollen basket on her hind leg. If you’re interested in spending time observing the series of different insect pollinators that visit Spring Beauty as the season progresses, there’s a golden opportunity for you. If you go to http://springbeauties.wordpress.com/ you can participate as a citizen scientist volunteer and participate in their survey.
Many shrubs really come into their own in the spring when they flower — not necessarily big, flashy flowers, but more subtle and delicate blossoms, with beautiful colors and designs. Beaked Hazel (Corylus cornuta) is such a shrub. Its female flowers are now blooming – exquisite little maroon flowers with magenta highlights and pistils that curl this way and that in hopes of catching pollen. One advantage to flowering before leaves are out is that there is less interference with pollen dispersal. The entire flower is less than 1/4” in diameter.
It’s hard to believe, but even after Irene, several inches of snow and an occasional night that’s below freezing, there are still butterflies and moths to be seen. Yesterday this sulphur butterfly (probably clouded, Colias philodice) was flying from dandelion to dandelion, sucking up nectar with its long, black proboscis. Clouded sulphur and orange sulphur butterflies, two different species, are similar looking, and on top of that, they even hybridize, so distinguishing between the two is often difficult, at best. Both species have several broods in a summer; you can see them flying in fields and along roadsides from spring to fall.
The downward “nodding” curve of its tubular flowers gives Nodding Ladies’ Tresses (Spiranthes cernua) part of its common name. ( I’m not sure where the reference to tresses, or a woman’s long locks or braid of hair, comes from.) The bright white flower spike of this relatively common member of the Orchid family stands out in moist meadows of green grasses. A perennial, Nodding Ladies’ Tresses grows between 4 and 12 inches tall, and is pollinated by both long and short-tongued nectar-seeking bees.
If you want to get an idea of the number and variety of wasps, bees, beetles and bugs that reside in your area, go to the nearest goldenrod patch sit for a spell – this member of the Aster family is a magnet for insects. You’ll find many foliage- eating bugs and beetles, leaf-mining larvae, nectar and pollen feeders, and flower and seed-eaters. In addition, many predatory spiders (jumping and crab, especially) and insects (ambush bugs, ladybug beetles, flower bugs etc.) have discovered that goldenrod is a goldmine for them, as well. Researchers have found nearly 250 species of insects feeding on one species of goldenrod (Solidago canadensis). Pictured from left to right are a long-horned beetle (locust borer, Megacyllene robiniae - pollen eater), a fly (nectar feeder) and bee (nectar and pollen feeder).
Ruby-throated Hummingbirds, New England’s only species of hummingbird, are a major pollinator of flowers. As they hover at flowers, often red like the pictured bee-balm, hummingbirds probe their bill down into the flower’s nectaries in order to reach the nectar. As they do so, the anthers of the flower brush against the hummingbird, often on top of its head or on its face, depositing pollen. Some of this pollen is likely to fall off on the strategically placed stigma of the next flower it visits (often the same species). Research in Illinois and Missouri confirms that ruby-throated hummingbirds deposit ten times as much pollen (per stigma per visit) as do bumble bees and honey bees! The diet of hummingbirds is not limited to nectar, however. Insects, including caterpillars, mosquitoes, spiders, gnats, fruit flies and small bees, are gleaned from leaves and bark, as well as captured in air. The sap holes drilled in trees by yellow-bellied sapsuckers attract insects which hummingbirds consume along with the sap.