Athena ‘Emer I’ Classic Lacebark Elm Lineage Ulmus parvifolia (Chinese elm, Lacebark elm, Drake elm). Also known as ‘Emerald Isle’. PP7551 Introduced in 1989 (Dave’s Garden, 2011). Tree Form A medium-sized tree with a broad rounded canopy, often with a trunk that forks resulting in a vase shape similar to that of the American elm (Floridata, updated 11/18/2010). Tree size, leaf size and growth rate half of that of the American elm, and they are often planted as a single tree (Warren, 2000). Height: 30 to 40 feet Width: 35 to 45, up to 60 foot wide crown spread (Delmar Learning, undated; UConn, undated)) Foliage Dark green in summer, leathery, almost black; bronze to bronze-brown in fall (Cornell, undated). Leaves simple, 1 to 2 inches long, but half as wide. Ovate, margins rounded to serrate (Delmar Learning, undated). Late deciduous, almost evergreen in mild climates (Floridata, 2010). Culture NA Disease and Insect Information Literature (Dutch elm disease studies, insect resistance assessments, etc.): Resistant to Dutch Elm Disease (DED), phloem necrosis and Elm Leaf Beetles (Delmar Learning, undated). It resists DED and shows very good performance under dry conditions (UConn, undated). Completely immune to Gypsy Moth, and only 10% of the leaf tissue was consumed by Japanese Beetle, the lowest of all the asian elms tested in a no-choice study (Paluch et al., 2006). When the Japanese Beetles were given a choice of species they did not feed on the U. parvifolia at all (Paluch et al., 2006). In an earlier similar study, U. parvifolia was the most resistant of all cultivars and hybrids to the Japanese Beetle (Miller et al., 1999). In Italy the tree was found by Mittempergher to have the lowest level of susceptibility to DED and Elm Leaf Beetle in natural infections (Mittempergher and Santini, 2004). National Elm Trial: In Kentucky in 2007, ‘Athena’ was tied for the third lowest level of defoliation by Japanese beetle at only 15 percent (range was 2 to 87 percent) (Hartman et al., 2007). Winter Hardiness USDA Zones 5 to 9 National Elm Trial: In artificial freezing tests at the Morton Arboretum the LT50 (temp. at which 50% of tissues die) was found to be -34 ⁰C (-29 ⁰F) (Shirazi and Ware, 2004). In Kentucky, ‘Athena’ suffered no shoot or leaf freeze damage, nor any trunk or bark damage in 2007 (Hartman et al., 2007). Experienced greater than 50% mortality during the first year of planting at the elm trial in Holbrook, Arizona (Elm Plantation Study, 2008). Literature Elm Plantation Study. Updated 10 July 2008. Northern Arizona University, College of Engineering, Forestry & Natural Sciences: School of Forestry. Available at: http://www.for.nau.edu/cms/content/view/512/706/. Hartman, J., E. Dixon, D. Potter, C. Brady, J. Edelen, J. Hart, and W. Fountain. 2007. National Elm Trial-Kentucky Data, 2007. UK Nursery and Landscape Program Overview-2007. pp 35-6. Available at: http://www.ca.uky.edu/agc/pubs/pr/pr554/pr554.pdf. Mittempergher, L. and A. Santini. 2004. The history of elm breeding. Investigación agraria: Sistemas y recursos forestales 13(1): 161-177. Available at: http://revistas.inia.es/index.php/fs/article/view/821/818. Miller, F., S. Jerdan, and G. Ware. 1999. Feeding Preference of Adult Japanese Beetles (Coleoptera: Scarabaeidae) for Asian Elm Species and Their Hybrids. Horticultural Entomology 92(2): 421-426. Paluch, G., F. Miller, J. Zhu, and J. Coats. 2006. Influence of Elm Foliar Chemistry for the Host Suitability of the Japanese Beetle, Popillia japonica, and the Gypsy Moth, Lymantria dispar. Journal of agricultural and urban entomology 23(4): 209-223. PlantFiles: Chinese Elm, Lacebark Elm; Ulmus parvifolia 'Athena'. Dave’s Garden. Available at: http://davesgarden.com/guides/pf/go/89725/. Shirazi, A. M. & Ware, G. H. (2004). Evaluation of New Elms from China for Cold Hardiness in Northern Latitudes. International Symposium on Asian Plant Diversity & Systematics 2004, Sakura, Japan. Ulmus parvifolia ‘Athena’. Undated. Available at: http://www.delmarlearning.com/companions/content/0766836347/pdf/Bridwell_455.pdf. Ulmus parvifolia, Chinese Elm, Lacebark Elm, Ulmaceae. UConn Plant Database. Available at: http://www.hort.uconn.edu/plants/u/ulmpar/ulmpar1.html. Warren, K. 2000. The Return of the Elm; The Status of Elms in the Nursery Industry in 2000. J. Frank Schmidt & Son Co. Available at: http://www.ces.ncsu.edu/fletcher/programs/nursery/metria/metria11/warren/elm.htm #837 Ulmus parvifolia. Updated 2010 November 18. Floridata.com. Available at: http://www.floridata.com/ref/U/ulmu_par.cfm. Ulmus parvifolia ‘Emer II’ Allee® Elm Lineage Ulmus parvifolia Jacq. (Chinese Elm or Lacebark Elm) U.S. Plant Patent #7552 issued June 11, 1991 (Missouri Botanical garden, 2011). Originally produced by M.M. Glenn, J.H. Barbour, and M.A. Dirr in 1991. First published as “Emerald Vase”, but later trademarked as “Allee”. Selected on the University of Georgia campus in Athens from a tree that was planted circa 1910, was 80-90 years of age, and had a vase-shaped crown of 70 feet high by 59 feet wide (Wikipedia, 2010). Tree Form Upright vase shape, dense canopy, arching, spreading form, some trees similar to that of Ulmus americana, with upright-spreading branches, while others are broader than tall with broad-spreading branches. Height: 60-70 feet Width: 35-55 foot crown spread, or 50 to 65 feet wide (Missouri Botanical Garden, 2011; Monrovia, 2011; Stadler Nursuries, 2011). Foliage Ovate-elliptic leaves to 2” long with serrate margins, acuminate tips and asymmetrical bases. Medium green, glossy leaves, turning orange to rust red in the fall (Missouri Botanical Garden, 2011). Culture Produced from own root, and by tissue culture. Disease and Insect Information Literature (Dutch elm disease studies, insect resistance assessments, etc.): Highly resistant, but not immune, to Dutch Elm Disease. The Elm Leaf Beetle, Xanthogaleruca luteola, was reported to have caused no defoliation in 1999, and only very slight defoliation in 2000 of ‘Allee’ (Elm Leaf, undated). Of the 24 U. parvifolia cultivars tested, ‘Allee’ was the only one with any damage at all (Elm Leaf, undated). Damage caused by the Japanese Beetle and by aphid pouch galls is relatively slight, but the damage by leafminers was moderate (Brady et al, 2008). According to the Missouri Botanical Garden Kemper Center for Home Gardening “ALLEE has excellent resistance to Dutch Elm Disease and Elm Leaf Beetle. It also has excellent resistance to leaf scorch, dieback symptoms and cold winter weather. Phloem necrosis, wetwood, various wilts, rots and cankers may occur. Insect visitors may include borers, leafminer, beetles, mealy bugs, caterpillars and scale” (Missouri Botanical Garden, 2010). Completely immune to Gypsy Moth, and only 10% of the leaf tissue was consumed by Japanese Beetle, the lowest of all the asian elms tested in a no-choice study (Paluch et al., 2006). When the Japanese Beetles were given a choice of species they did not feed on the U. parvifolia at all (Paluch et al., 2006). In an earlier similar study, U. parvifolia was the most resistant of all cultivars and hybrids to the Japanese Beetle (Miller et al., 1999). In Italy, the tree was found by Mittempergher to have the lowest level of susceptibility to Dutch Elm Disease and Elm Leaf Beetle in natural infections (Mittempergher and Santini, 2004). National Elm Trial: In Lexington, Kentucky, in 2007, “Emer II Allee’ exhibited the lowest amount of damage due to the Japanese Beetle at only 2 percent defoliation (Hartman et al., 2007). Winter Hardiness USDA Zones 5 to 8 National Elm Trial: In the elm trial at Northern Arizona University ‘Emer II’ (Allee) was apparently unable to survive the hot and dry climate as over 50% of the trees planted sustained mortality within the first year of planting (Elm Plantation Study, 2008). Likewise, at UC Davis, all five of their trees perished within the first year of planting. Except for one ‘Frontier’ tree also perishing, these were the only trees that died (McPherson et al., 2008). On the other hand, ‘Allee’ was able to withstand cold winter temperatures in Kentucky better than other cultivars. It did have some trunk cracking occurring, but it did not have any shoot or leaf tissue freeze damage in the trial there in 2007 (Hartman et al., 2007). Literature Allee® Chinese Elm; Ulmus parviflora 'Elmer II' P.P. 7552. 2011. Monrovia. Available at: http://www.monrovia.com/plant-catalog/plants/368/allee-chinese-elm.php. Allee Elm (Ulmus parvifolia). 2011. Stadler Nurseries. Available at: http://www.stadlergardencenters.com/trees/index.php?tid=1041. Brady, C., J. Condra and D. Potter. 2008. Resistance of Landscape-suitable Elm (Ulmus spp.) Cultivars to Japanese Beetle, Leaf Miners and Gall Makers. 2008 Research Report, Nursery & Landscape Program. University of Kentucky. pp 15-16. Available at: http://www.ca.uky.edu/agc/pubs/pr/pr571/pr571.pdf. Elm Leaf Beetle Survey. Undated. Sunshine Nursery & Arboretum. Available at: http://www.sunshinenursery.com/survey.htm. Elm Plantation Study. Updated 10 July 2008. Northern Arizona University, College of Engineering, Forestry & Natural Sciences: School of Forestry. Available at: http://www.for.nau.edu/cms/content/view/512/706/. Hartman, J., E. Dixon, D. Potter, C. Brady, J. Edelen, J. Hart, and W. Fountain. 2007. National Elm Trial-Kentucky Data, 2007. UK Nursery and Landscape Program Overview-2007. pp 35-6. Available at: http://www.ca.uky.edu/agc/pubs/pr/pr554/pr554.pdf. McPherson, G., L. Costello, J. Harding, S. Dreistadt, M. L. Flint and S. Mezger. 2008. National elm trial: Initial report from Northern California. Western Arborist, Fall 2009. pp. 32-36. Available at: http://gis.fs.fed.us/psw/programs/cufr/products/CUFR_780_Elm_trials_2009.pdf. Mittempergher, L. and A.