Plant Life in the Conservation District
Trees that predominate are oaks, American beech, and black birch, with a few maples and birch. Beneath the trees are many native blueberry bushes, clethra (summer sweet), and mountain laurel.
Wild Flowers and Plants
Throughout the woods are thinly scattered wild flowers. These include the pink lady’s slipper, May apple, False Solomon’s seal, and Canada mayflower.
Plants found along edges of the woods, particularly near the river, are wood aster, bayberry, sassafras, rosa rugosa, sweet fern, and sumac.
Plants found on the banks of York Pond at the end of Irving Avenue are elderberry, Joe Pye weed, goldenrod, bur cucumber, white snakeroot, evening primrose, milkweed, and touch-me-not (jewelweed). curly dock, blue vervain, polygonum persicaria (lady’s thumb—pink thumblike flowers), and false nettle, chicory along the rail north of the entrance to York Pond meadow, and blue flowering pickerel weed in the pond.
The most prevalent invasive species in the park are: Oriental Bittersweet, Japanese Knotweed, Tree of Heaven (Ailanthus), Purple Loosestrife, Garlic Mustard, and Multiflora rose. Poison ivy, which grows throughout the park, is a native plant.
Most of these were introduced to the area by horticulturists as garden ornamentals. An exception is garlic mustard, which was introduced as a food plant. Japanese Knotweed, Purple Loosestrife, and Oriental Bittersweet are particularly invasive and difficult to eradicate. Introduced plants that become invasive have particular habits that make them more successful than native plants, for example a long growing season, long tap roots to reach water, chemicals that weaken neighboring plants, and ability to tolerate harsh conditions. These plants tend to crowd out the native plants that local wildlife need for food and habitat. In the Conservation District, one instance of a native – invasive “mismatch” occurs when monarch butterflies lay their eggs on (invasive) black swallow-wort instead of native milkweed. Black swallow-wort is in the milkweed family, but the young monarch caterpillars cannot digest its leaves so they die.
List of Plants by Rick Enser (2001)
* indicates non-native to the U.S.A.
Woodlands: Uplands and Woods Edges
Non-native plants found in Blackstone Park
These have a tendency to be invasive.