1 Warbler In the spring and summer, stop and listen for the clear and musical sounds of warblers. Some of the common recognizable songs you may hear are of the yellowthroat (wichety wichety wichety), the yellow warbler (a rambling song often ending with sweet sweet sweet ti ti ti to soo), and the chestnut-sided warbler (witew witew witew weechew). If you are patient enough to see the birds, you will discover that the males have brightly colored feathers during the breeding season. These small birds spend their winters in the tropics and migrate long distances over the Gulf of Mexico in the spring. A number of these neotropical migrant populations have declined in recent years as a result of habitat loss in the tropics and fragmentation of the forests in their summer breeding areas. The open fields around the forest fragments have provided suitable habitat for the brown-headed cowbird, leading to its increased abundance. The cowbird lays its eggs in the nests of songbirds. The rapidly growing cowbird hatchlings steal food from the hosts, decreasing their reproductive success. You can recognize the male cowbird by its brown head contrasting with its black body and glossy green feathers. 2 Poison Hemlock (Conium maculatum) This highly toxic herb was probably the source of the poison which Socrates drank. You may notice the unpleasant, pungent smell of the plant from a distance. The many small white flowers occur in an umbel, an arrangement of flowers that resembles an umbrella. Poison hemlock is found in wet places. It is related to and resembles Queen Anne’s lace, a common weed of dry fields. In the winter, you can see the dead stalks standing eight-feet tall. Consumption of poison hemlock is usually fatal. Please do not touch this plant. 3 White Ash (Fraxinus americana) This is one of a small number of tree species with branches that are located opposite one another. Other species include maple and arrowwood. Most trees have alternate branching. The older bark of white ash is gray and forms pointy, diamond-shaped ridges. The wood is used in making baseball bats, tool handles, and furniture. The low-growing plant found in summer and early fall in the wet area under this ash is yellow monkey flower (Mimulus moschata). The shape of the flower resembles a grinning face. It is a relative of the snapdragon. 4 Our Changing Forests The trees of a forest may change due to disease as well as succession. The spread of disease has become more common as a result of human activities. Two trees formerly found in this forest, the American elm (Ulmus americana) and American chestnut (Castanea dentata), were decimated by disease. North America has been hit with two waves of Dutch elm disease, the second wave threatening the American elm with extinction. The disease crossed the Atlantic Ocean from northwestern Europe on shipments of logs probably several times around 1930. The disease is a fungus that is introduced into healthy trees by the elm bark beetle. As the larvae of the beetle burrow into the wood, the fungus is spread. Chestnut blight has either eliminated or reduced most of the American chestnut trees to understory shrubs. Sprouts continue to arise from the surviving roots of the once massive, wide-spreading trees, but they rarely reach sexual maturity. The fungus causing the disease was introduced into North America with horticultural material from eastern Asia and was first noticed in New York in 1904. Yet another fungus is currently affecting the American beech, something we’ll cover in more detail at #12. 5 Musclewood (Carpinus caroliniana) Witch Hazel (Hamamalis virginiana) The trunk of musclewood is fluted and appears muscular. The smooth bark of this small tree is blue-gray. The elliptical leaves are doubly toothed at the edges, resembling the leaves of birch trees. Witch hazel is an unusual shrub in that it blooms in autumn after it has dropped its large, ruffle-edged leaves. The bright yellow flowers are pollinated in late fall, and the nutlike fruits become mature a year later. The mature fruits explode, spreading the seed as far as 20 feet. 6 Spring Wildflowers In May and June you will be rewarded with the blooms of many spring flowers along the trail. Most spring wildflowers require the moist, shaded habitat of the forest. Trillium (Trillium spp.) takes its name from the prefix “tri” meaning three. Trillium has three veined leaves and a three-petaled flower. One species has maroon flowers and is called stinking Benjamin (T. erectum). Can you discover how it got this common name? Another has white (T. grandiflorum), and a third has white with a red blaze (T. undulatum) The flower of foamflower (Tiarellla cordifolia) resembles a puff of shaving cream. Wild geranium (Geranium maculatum) has pink flowers with five petals. The single, waxy, white flower of May apple (Podophyllum peltatum) is found at the base of the two large leaves which resemble beach umbrellas. Younger plants possess a single leaf and no flower. 7 Primary Succession The flat gray-green organisms growing on these rocks are lichens. Lichens are a product of two different species living closely together - a fungus and an alga. Studies have shown that the fungus obtains most of the food produced by the photosynthetic algae. Lichens are pioneers of primary succession. They grow on rocks and very slowly break the rock into soil. Succession proceeds as mosses and other plants grow on the lichen-formed soil. 8 Ferns Most of the plants observed so far disperse themselves by forming seeds within a fruit or within cones in the case of the hemlock tree. Along the trail you will find ferns, clubmosses, and mosses, which reproduce by germination of single cells called spores. These plants do not produce seeds. The underside of the lace-leaf woodfern (Dryopteris intermedia) is covered with small brown dots containing the microscopic spores. Spores are often dispersed by wind or water. Christmas fern (Polystichum acrosticoides) grows in clumps and may be seen poking through the snow in winter. Its spores are only found on the undersides of the leaflets at the tip of the leaf. The leaflets of this evergreen fern are shaped like Christmas stockings, giving its common name. 9 Basswood (Tilia americana) Interpreting nature makes use of all of your senses. Thump the trunk of the basswood tree with the palm of your hand. It will sound hollow like a watermelon. The bark is dark gray with deep furrows. The large heart-shaped leaves make identification easy in spring and summer.