| Ulmus hybrid | |
|---|---|
'Triumph', aged 4 years, Great Fontley, UK |
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| Details | |
| Hybrid parentage | 'Morton' (Accolade) × 'Morton Plainsman' (Vanguard) |
| Cultivar | 'Morton Glossy' = Triumph™ |
| Origin | USA |
The elm cultivar 'Morton Glossy' (Triumph) was originally known as 'Charisma' until it was realized that name had already been registered for another plant. The tree was derived from a crossing of two hybrids grown at the Morton Arboretum, 'Morton' (Accolade) and 'Morton Plainsman' (Vanguard).
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'Morton Glossy' (Triumph) has been promoted in the USA as "strong and symmetrical" in growth and habit [2]. However, its performance in the southern United States has not impressed, and it was dismissed, along with its stablemates 'Morton Stalwart' and 'Morton Plainsman' as "ugly" by Michael Dirr, Professor of Horticulture at the University of Georgia [3], on account of its "wild" growth and splaying branches, a judgment confirmed by trials in the UK [1]. The leaves are a deep glossy green when mature, < 10 cm in length by 5 cm broad, with rough upper surface and finely toothed margins. 'Morton Glossy' (Triumph) is one of the first elms to shed its leaves in the fall, usually by early October.
In commerce, the tree is propagated by grafting onto an Ulmus pumila rootstock.
Resistant to Dutch elm disease, 'Morton Glossy' (Triumph) is highly susceptible to attack by elm leaf beetle Xanthogaleruca luteola [4] [2] [5] and Japanese beetle [3] [4].
The tree, under its original name of 'Charisma', featured in the elm trials [6] conducted by Northern Arizona University at Holbrook, eastern Arizona. 'Morton Glossy' is very cold-hardy; in artificial freezing tests at the arboretum [5] the LT50 (temp. at which 50% of tissues die) was found to be - 40 °C.
The tree is currently being evaluated in the National Elm Trial[7] coordinated by Colorado State University.
'Morton Glossy' Triumph was commercially released in the UK in 2005 (180 sold in 2006). Several specimens were acquired for assessment by Butterfly Conservation in Hampshire [1]. It has grown quickly if untidily at most sites, although its stem has proven weak and unable to support its burgeoning crown, necessitating continued staking. Moreover, unlike 'Morton' (Accolade), it has also proved intolerant of ponding on poorly-drained soils over winter.