Morton Accolade™ is an
elm
cultivar derived from a
hybrid planted at the
Morton Arboretum in
1924, which itself originated as
seed collected from a tree at the
Arnold Arboretum in
Massachusetts. although this tree
was originally identified as
Ulmus
crassifolia, it is now is believed
to have been a hybrid of the
Japanese Elm Ulmus davidiana
var.
japonica and Wilson's Elm,
the latter now sunk as another form of
Ulmus davidiana var.
japonica.
The tree at the Morton Arboretum was
noted for the resemblance of its habit
to the
American Elm Ulmus americana,
its upright-arching branches creating
the familiar vase-shape. Moreover, in
its 80+ years it had survived three
epidemics of
Dutch Elm Disease there unscathed.
However, two trees included in trials at
the
University of Minnesota were found
to be afflicted by the diease in 2004,
although one appears to have recovered
completely. 'Morton' has now been cloned
and promoted by the
Chicagoland Grows corporation as a
potential substitute for the innumerable
American Elms lost to disease, although
the tree does not grow as large as the
iconic native elm, reaching scarcely 20
m at maturity; its glossy, deep green
leaves are also markedly smaller.
'Morton' is reputed to grow well in
almost all soils save those excessively
wet, and is notably drought-tolerant and
winter hardy. The tree grows vigorously
at first, gaining as much as one metre
per annum, but slows to approximately
half that rate with maturity. Thus, a
typical 20 year-old tree could be
expected to have reached 10 m in height
with a crown about 5 m in width.
'Morton' has also proved to be highly
resistant to
elm yellows and the
elm leaf beetle. It is currently
being evaluated in the National Elm
Trial coordinated by
Colorado State University.
The tree will not be commercially
available in Europe until at least 2010,
but specimens grown from selfed seeds
are featured in the
Butterfly Conservation elm
trials in
Hampshire,
England, where they have grown with
extraordinary vigour, and proven very
tolerant of local conditions, notably
waterlogged soils in winter.
Hybrid cultivars
Morton Accolade™ was crossed with the
hybrid cultivar
'Morton Plainsman' Vanguard™. A
selection of the resultant seedlings was
marketed under the name 'Charisma',
later changed to
'Morton Glossy' Triumph™. --From
Wikipedia, the free encyclopedia
