bur oak: medium to large deciduous oak of central and eastern North America with ovoid acorns deeply immersed in large fringed cups; yields tough close-grained wood
white oak: any of numerous Old World and American oaks having 6 to 8 stamens in each floret, acorns that mature in one year and leaf veins that never extend beyond the margin of the leaf
tylenchus: type genus of the family Tylenchidae