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Down to Earth
In this series of articles staff, students and graduates of Burnley College share their views with Global Garden readers on a range of topical horticultural issues. Burnley College is part of the University of Melbourne’s Institute of Land and Food Resources and enjoys an esteemed reputation as one of Australia’s premier horticultural institutions. Click here for a list of other articles in the series.

A pear by any other name.....
by James Will and Jill Kellow

Over the last 10 years, flowering pears have become increasingly popular, both in south-eastern Australia and throughout the world. Probably these trees are so widely used because of their moderate stature (typically under 6 metres), intense spring flowering, glossy summer foliage and excellent autumn colour. In the United States, many named selections of the species Pyrus calleryana have been released showing differing forms, adaptability to low winter temperatures, and leaf form.

In Australia, things are somewhat different. Since the early 1970's, most people associate the species Pyrus ussuriensis, or “Manchurian Pear” with flowering pears. This plant first appeared in the catalogue of Bert Chandler and Sons Nursery, located at the base of the Dandenong Ranges in eastern Victoria. This plant was widely propagated (typically by budding onto a rootstock selection of Pyrus calleryana), and may have formed the basis for the plantings found in Canberra and the eastern suburbs of Melbourne.

At Burnley College, we have a planting of about eight of these trees in our quadrangle area. As these trees matured, we noticed that they didn't match the descriptions of P. ussuriensis found in the literature. We decided to look further, and found that none of the trees in the eastern streetscapes matched the “official” descriptions found in flora or
other publications. With the help of the Herbarium of the Royal Botanic Gardens, Kew and other herbaria throughout Australia, we were able to determine that the tree sold as “Manchurian Pear” was not P. ussuriensis at all. What is sold here is obviously a form of P. calleryana. We are not certain how the names became mixed, or what cultivar of P. calleryana we may have. A more exact description of this plant can only be developed through chemotaxonomic techniques.

This information is extremely important, since the common “Manchurian Pear” of south-eastern Australia grows differently from true P ussuriensis. The “Manchurian Pear” we are growing has extremely poor branch attachment, making it a liability for many landscapes. Recently we have noticed that many of the “Manchurian Pears” in the Melbourne landscape show evidence of splitting or limb loss. Here at Burnley, two of our trees have split completely, with the remainder showing evidence of extremely poor form.

Until known Pyrus ussuriensis trees are available from nurseries, we recommend planting
the two named varieties of P. calleryana currently available. These selections, 'Red Spire' and 'Bradford' are better-formed trees for the Australian landscape. Soon, true P. ussuriensis will be available, along with additional P. calleryana selections. If we're lucky, we may also soon have the Australian-selected form 'Claremont' available from the Waite Arboretum.

Illustration above: The unknown form of Pyrus calleryana growing at Burnley College

About the Writers:
James Will is a Senior Lecturer in Horticulture and Plant Breeding at Burnley College with a special interest in roses.
Jill Kellow is a Technical Officer at Burnley College whose particular forte is her knowledge of plant materials.

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