Betula kenaica Betula kenaica Betula kenaica, or Kenai birch, is a species of birch that can be found in Alaska and northwestern North America at above sea level. It grows up to tall, with reddish-brown bark that may become pink or grayish-white. The leaf blades are ovate and grow in 2-6 pairs which are (sometimes up to ) long and wide. The leaf margins are cuneated and serrated with rounded base and acute apex. The flowers bloom in late spring while fruits fall in autumn. The buds and twigs of the plant are used as a stew flavor while its inner bark
Pterocarya fraxinifolia appear in April, the male catkins thick and green, 7.5 – 12.5 cm long, the females longer with less dense flowers, bearing red styles forming fruiting catkins 30 – 50 cm long, the green, winged, nuts approximately 1.8 cm wide. The species is fast growing and grows best on flat ground or shallow slopes near river banks and in deep moist soils. The climate associated with the distribution of this tree includes mild winters and mild humid summers. It generally grows in mixed stands with other species and rarely grows in pure stands. Fossils of "Pterocarya fraxinifolia" have been described