on southwestern faces of some of the southernmost hillsides pine predominates and there is also the occasional prickly pear cactus, which grows naturally. in contrast, some of the northeastern aspects are most likely to have small but dense stands of moisture loving hemlocks and mosses in abundance. other commonly found plants include oak, hickory, chestnut, maple, tulip poplar, mountain laurel, milkweed, daisies, and many species of ferns. the once predominant american chestnut tree was effectively brought to extinction by a fungus known as the chestnut blight during the 1930s – though the tree continues to grow in the park, it does not reach maturity and dies back before it can reproduce. various species of oaks superseded the chestnuts and became the dominant tree species. gypsy moth infestations beginning in the early 1990s began to erode the dominance of the oak forests as the moths would primarily consume the leaves of oak trees. though the gypsy moths seem to have abated some, they continue to affect the forest and have destroyed almost 10 percent of the oak groves.