 The American chestnut "C. dentata" served as an important source of lumber, because it has long, unbranched trunks.In Britain, chestnut was formerly used indiscriminately with oak for the construction of houses, millwork, and household furniture.It grows so freely in Britain that it was long considered a truly native species, partly because the roof of Westminster Hall and the Parliament House of Edinburgh were mistakenly thought to be constructed of chestnut wood.