Despite the common names ringworm and dermatophyte, the disease is caused by a fungus, not a worm or plant. Trichophyton, Microsporum, and Epidermophyton are the most common genera that cause ringworm in humans. These organisms feed on keratin, the major structural component of hair, skin and nails.
Thuja occidentalis 'Nigra'. Naturally broad, pyramidal evergreen shrub displays deep green, scalelike needles arranged in flat sprays. New light green needles emerge in spring, deepening in color as they mature. Deep green color adds contrast to winter landscape.
Species Heights. Betula nigra, or the river birch, grows throughout USDA zones 4 through 9. One of the hardiest species, it has peeling, light brown park and small, true green leaves. This tree has a rounded canopy and grows to a maximum height of 70 feet and width of 60 feet.