American Chestnut

(Castanea dentata)

Fagaceae (Beech Family)

▲ young tree at Minnesota Arboretum

▲▼ leaves

▲ flowers

▲ fruit

▲ bark and trunk

Location on or near campus:  not known

·         Castanea dentata: American Chestnut

·         leaves similar to sawtooth oak, large growing tree with spiny fruit enclosing large edible nut; very large growing tree

·         native to eastern 1/3 of U.S., but essentially killed out by chestnut blight (disease) in first half of 20^th century

    §  is a fungal disease spread by air and root grafts, causing cankers and stem/branch die back

    §  stumps re-sprout and sometimes live long enough to produce nuts

§  only stump sprouts remain of in regions of original trees

·         extensive work going on to produce disease-resistant chestnuts by either:

    §  selecting seedlings that appear more resistant and cross-breeding them, then selecting most resistant seedlings to cross again—takes 10-15 years from nut to flowering, so many years required to achieve fairly resistant trees—they are starting to release some cultivars now

    §  crossing American chestnut to resistant Chinese chestnut, then crossing resistant seedlings back to American to get more of the American traits—single, straight trunk, tall tree; sweeter nut—but hopefully keeping the resistance from the Chinese chestnut in the offspring—again, takes a long time, and just now, some hybrids are entering market