Silver Birches or the Similar Japanese White Birches are very common though along with Oaks and of course heaps of Bamboo too keep the bears happy and with full stomach so they don't go mauling any unsuspecting ramblers, still most people do (myself included) carry little cow bells just to let the bears know, if they happen to be around, that someone is passing through.
Poison Ivy
Here's a surprise too, I don't know how common this really is in Britain but i could always remember when i was young back in the 70's hearing about Posion Ivy. It began to seem like a myth when one never came across it but in the forests of Togakushi it is rife, in abundance along with the Poison Sumac or Urushy as the Japanese call it which is quite an apt name as the toxic ingredient contained within the plant that causes a nasty blistering rash in some people is Urushiol. And yes I happened to be one of those people, at least the rash from hell only lasted for 3 weeks! Lovely looking climbing vine though nevertheless. We have also got some really beautiful butterflies in this neck of the woods.
Old World Swallowtail - Papilio machaon
Ideopsis similis - Asagimadara Butterfly
Swallowtail Butterfly - Papilio spp.