Tryphaetha-trees

Elves do not plough land and grow crops the same way that other mortal races do.  In the territory of elven holds grow enormous Tryphaetha-trees with leaves often four or five feet across and branches spreading hundreds of feet, whose trunks are grown and shaped into long walls or numerous pillars.  These trees are grafted with other types of trees which have been specially bred to produce particular types of fruit or vegetable produce.   Tryphaetha-trees can grow extremely quickly, but require constant training and shaping using a complex semi-alchemical process of gardening by elves known as 'shapers'.  Often these trees are shaped to form grand shared dwellings for elves, as well as menial structures like bridges or water-channels and public buildings as well as providing plentiful sustenance for the population of an elven settlement.   Tryphaetha-trees do not grow well without shaping and barely grow at all outside elven realms.  Even without magic, a specific and constant cycle of land-care and worship is necessary for them to grow at all.