**Description:** The State Tree of Pennsylvania. A graceful coniferous evergreen with small, flat needles and tiny cones.
**Size:** Reaches 100+ feet; can live for over 300 years.
**Sexual Dimorphism:** Monoecious; produces small yellow male cones and larger woody female cones.
**Conservation:** Highly threatened by the invasive Hemlock Woolly Adelgid.
**Habitat:** Cool, damp ravines and north-facing slopes.
**Behavior:** Provides critical shade to keep mountain streams cold enough for Brook Trout.