Ancient Latin name.
The following account is based on the booklet Elms in Australia by R Spencer, J. Hawker, and P. Lumley, Ornamental Plants 3. Royal Botanic Gardens, Melbourne (1991).
Deciduous and evergreen trees. Bark grey and fissured (U. parvifolia is a small to medium sized evergreen or semi-evergreen tree with orange-brown scaling bark). Leaves simple, alternate, generally unequal at the base, toothed, prominently pinnately veined; colouring yellow in autumn. Flowers bisexual, in small inconspicuous clusters before the leaves. Petals absent. Stamens 4-5; early spring. Ovary superior, 1-chambered with 1 ovule. Fruit a green, red or purple achene, surrounded by 2 green to yellowish papery wings that are notched at the tip; ripening and shed just as the new leaf buds are breaking.
In Victoria the autumnal yellowing of the leaves generally begins slowly at the end of March, the deciduous trees finally losing all leaves by about mid June. Flowers appear at the beginning of September and fruits develop towards the end of this month; these fall in large quantities as confetti-like showers in mid October that, for a brief period, form small drifts in gutters and along roadsides.
With the exception of Ulmus parvifolia and U. glabra, seed is mostly infertile so propagation is by semi-hardwood cuttings and layers or, in the case of special clones and cultivars, budding and grafting. The Melbourne City Council now buds selections on to the non-suckering stocks of U. glabra that have been grown both from seed and cuttings.
Leaves unequal at the base; fruits forming small, papery disks.
About 25-30 species (depending on the botanical authority) mostly from the temperate northern hemisphere and with a centre of distribution in C and N Asia.
Green (1964), Jobling & Mitchell (1974), Melville (1975), Richens (1983), Yeo (1989b), Spencer et al. (1991), Santamour & Bentz (1995).
Elms, especially the Dutch and English Elms were widely grown as street trees and in park avenues (especially in Victoria) in the late 19th and early 20th century. As a result, many mature (sometimes commemorative) avenues remain between the age of 60-140 years. The devastation caused by Dutch Elm disease overseas, especially the United Kingdom and America, has meant that Australia (especially Victoria and Melbourne) now has some of the world's finest elm avenues, a few of which are listed below:
Melbourne avenues: Alexandra Avenue, Batman Avenue, Birdwood Avenue, Punt Road, Royal Parade
Public gardens: Carlton Gardens, Caulfied Park, Fawkner Park, Fitzroy Gardens
Country towns: Ballarat, Beechworth, Benalla, Bendigo, Camperdown, Colac, Skipton, Smeaton, Streatham, Traralgon
In New South Wales there are substantial plantings at Bowral, Orange, Bathurst, Wagga and Albury and the New England district. In Tasmania they are widely planted in the Midlands, Launceston, Ross, Port Arthur and Hobart. South Australia has trees in the Barossa Valley and Mt Gambier. At Canberra elms are widely grown, with mature specimens at the Australian National University, Westbourne Woods, Dunrossil Drive, Northbourne Avenue and elsewhere.
The English Elm and Dutch Elm are now unpopular because of the damage and expense caused by their suckers. However, the non-suckering Wych Elm, U. glabra, can be used as a stock for these and other suckering elms.
Historically the major nursery supplier of elms appears to have been C.A. Nobelius of Emerald, Victoria. Herbarium specimens held at the National Herbarium of Victoria show that several species and cultivars available at the turn of the century can no longer be obtained. Specimens from Nobelius dated 1900 and no longer available include the crisped and ornamental leaved U. glabra 'Crispa' and U. 'Viminalis Aurea'. Nobelius' nursery is no longer operational but many interesting mature trees (but not elms) remain on the Emerald site which may be visited by the public and is now known as Nobelius Heritage Park. The Waite Agricultural Research Institute Arboretum in Adelaide received from this nursery a range of species and cultivars that were planted in 1929, some of which remain, and are at least recorded as Herbarium specimens. There are also fine old elm trees at Port Arthur, Tasmania.
Taxonomy of the cultivated elms
The elms provide an excellent example of the difficulties encountered by botanists in deciding which are the true wild species in a group that has been in cultivation for several thousand years. Hybridisation and the use of selected clones has made it difficult to detect the original wild plants, especially as so few trees remain growing in nature.
There have always been widely diverging views on which are the true wild species of elm in England. The Wych or Scotch Elm (Ulmus glabra) is very distinct in its leaf and fruit characters and is found naturally in the colder northern and upland parts of Europe including Northern England and Wales. In contrast, other elms found in England are extremely variable in the shape, size and hairiness of their leaves and do not fall into distinct groups. It is unlikely that the true identity and origin of the elms growing in England will ever be satisfactorily resolved. One extreme view (Richens, 1983) is that, apart from U. glabra, there is only one other species, Ulmus minor (syn. U. carpinifolia), which has several subspecies, and hybridises with U. glabra to form a variable hybrid U.×hollandica, the Dutch Elm. According to this view, the elms of England were deliberately reintroduced after the last Ice Age. Different clones of the widespread and variable European species U. minor then hybridised with each other and with U. glabra in England. Since they produce mostly infertile seed and the plants sucker freely, the present population consists of a number of clones. At the other extreme is the view that the populations of different elms in England represent about five different species of fairly restricted distribution, together with a number of interspecific hybrids (Melville, 1975). This, view has been accepted by most botanists until recently.
The former view has much to recommend it but does not help greatly in naming the different elms in Australia. The latter view is backed up by Herbarium specimens in the National Herbarium of Victoria collected by Melville on a visit to Melbourne from Kew Gardens, London in 1952. However, in practice, using these specimens to identify the different elms is extremely difficult. This account follows an intermediate pragmatic view (Yeo, 1989b), which accepts three species: the Wych Elm, U. glabra, the Smooth-leaved or Field Elm, U. minor, and the English Elm U. procera. Various clones and some seeds have been introduced into Australia since the beginning of the last century. Deliberate planting of selected clones, combined with chance hybridisation, has resulted in a mix of elms rather different from that in England. The process is rather similar to that which Richens believed happened in England over a much longer period after the last ice age.
Dutch Elm Disease
Dutch Elm Disease is caused by the fungus Ceratocystis ulmi, which is fortunately unknown in Australia although its vector the Elm Bark Beetle Scolymus multistriatus was officially recorded in Victoria in 1974. These beetles and their larvae feed and breed on sickly or dying trees, often in the crotches of branches where they bore holes through the bark to the sapwood where they leave characteristic scribbles and engravings.
Elm Leaf Beetle
The discovery at Mt Eliza, in February 1989, of the chrysomelid Elm Leaf Beetle Pyrrhalta luteola is cause for further concern. This beetle (evident for 4 years in the area before its confirmation) is elm-specific. It overwinters as an adult that lays its eggs under the leaves in spring, the larvae hatching in one week and skeletonising the leaves before pupating in the soil below the tree or at the base of the trunk. Four generations may be completed in a year, causing severe damage. The presence of these beetles in Australia and the confirmation of Dutch Elm disease in central Auckland New Zealand on 3 January 1990 is cause for serious concern about possible outbreaks in Australia. The fungus that causes Dutch Elm disease grows to eventually block the water-conducting tissues. This produces the symptoms of leaf wilting and death on just a few branches at first, but eventually spreads throughout the tree. Friends of the Elms Society was formed in 1990 to support research into elm diseases and to monitor the future of the elm (http://www.friendsoftheelms.com.au/).
Identification is based largely on leaf characters. In the United Kingdom bark characters and general tree habit are sufficient to distinguish the commonly cultivated species (Mitchell, 1968; Jobling & Mitchell, 1974), but in Australia the characteristic forms of the different species and clones are generally obscured by pruning and tree surgery, and even mature, unpruned trees do not appear to have the definitive silhouettes and branching patterns of their European counterparts. Likewise bark texture is a variable character, even in the generally scaly-barked U. parvifolia. Flowers, which are usually so important in botanical identification, are present on the trees for only an extremely brief period. They are not of major significance in distinguishing the different elms. Leaves chosen for identification should be typical ones taken, if possible, from the crown. Care should be taken to avoid the frequently atypical leaves that appear on young, lower, sucker and epicormic shoots (those that develop from buds on the trunks). The most useful characters, apart from leaf shape, size and hairiness, appear to be vein number, the character of the lobing at the base of the leaf and the roughness of the upper surface. In some instances the young, exceptionally large and shaded leaves tend to show greater roughness. In the following account leaf stalks are measured on the long side; vein numbers refer to the number of strong veins that occur on the long side of the leaf excluding the tip; blade lengths occur from the tip of the leaf to the bottom of the leaf lobe.
The keys should be used with the illustrations as they do not take account of cultivars with unusual leaf shapes. To assist with identification two slightly different keys have been given.
Source: (1997). Ulmus. In: . Horticultural Flora of South-eastern Australia. Volume 2. Flowering plants. Dicotyledons. Part 1. The identification of garden and cultivated plants. University of New South Wales Press.