what kind of plants are found in these mountains?
Numerous  vascular plant species as well as many species of bryophyte, lichen, and macrofungi.
Oregon Caves National Monument and Preserve
Located within the Klamath–Siskiyou region, known for its high biodiversity, the monument supports 391 vascular plant species as well as many species of bryophyte, lichen, and macrofungi.
what is oregon caves national monument and preserve? It is a protected area in the northern Siskiyou Mountains of southwestern Oregon in the United States.
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Oregon Caves National Monument and Preserve [SEP] Flora and fauna
Located within the Klamath–Siskiyou region, known for its high biodiversity, the monument supports 391 vascular plant species as well as many species of bryophyte, lichen, and macrofungi. Trees in the monument include Douglas fir, oak, white fir, and alder. Among the oldest trees is Big Tree, thought to be the widest Douglas fir in the state. It is in circumference near the base. Its age is estimated at 600 to 800 years, and it was described in the 1930s as in diameter. The monument contains no plants with special conservation status. Species lists for the park include about 50 mammals, 86 birds, 11 reptiles and amphibians, 8 bats, more than 200 arthropods, 8 snails and slugs, 75 butterflies, more than 55 moths, and 8 aquatic macroinvertebrates.