What is "sequoiadendron"

Sequoiadendron is a genus of evergreen trees, with two species, only one of which survives to the present:

• Sequoiadendron giganteum, extant, commonly known as the "giant sequoia", growing naturally in the Sierra Nevada of California
• † Sequoiadendron chaneyi, extinct, the predecessor of Sequoiadendron giganteum, found mostly in the Nevada part of the Tertiary Colorado Plateau until the late Miocene