An abeltree is a tree with the Latin name populus alba, which is widely grown in North America.
There are 788 in Webster's Second International. Here's a small sample: grep -xE '([^e]*e){3}[^e]*' /usr/share/dict/words |grep ^........$ abeltree Aberdeen abietene absentee Acemetae acheweed aesthete aethered affeerer aftereye agueweed aiseweed Alberene antecede appellee arrestee assessee axletree ayegreen Baedeker bargeese beanweed beaupere beavered bebelted bebreech bedeafen beebread beefhead beefless beehouse beetrave beferned befetter befezzed begetter begrease beheader behearse