Pyrus ussuriensis var. ovoidea
Family: True Manchurian or Ussurian Pear
This tree has been widely misnamed in Australia. Until trees became available in 1999, all trees in Australia labelled ‘Pyrus ussuriensis’ were instead a clone of Pyrus calleryana, possibly an understock selection. These poor-quality clones of P. calleryana have shown significant problems with poor limb attachment, and a tendency to split when about 8m tall.
True Pyrus ussuriensis have been propagated from a single tree found in the Mt Lofty Botanic Gardens, South Australia. The original seeds are of the ovoidea variety, collected by Dr. David Symon on a trip to Manchuria. These trees are larger in scale than the incorrect Manchurian Pears and show significantly better branch attachment and obviously larger foliage. True P. ussuriensis var. ovoidea have excellent bronze-to-burgundy autumn colour and will grow into an excellent tree to approximately 12m tall.
All of the ornamental pears grow best in sites where water is retained in the soils throughout summer. They are especially well-suited for soils where there is a high clay fraction and also where there may be some compaction. Although they have not been widely planted in Melbourne, we expect that they will become up to 7m in width, and are well-suited for planting in parking areas, on major streets, and in parks. The root systems of these Pyrus (grafted on P. calleryana) are vigorous, but should not lift paving unless extremely restricted.
P. ussuriensis var. ovoidea differs from P. ussuriensis in that it has an ovoid fruit to 3cm in diameter. This pear fruits very lightly unless it is planted near other pears such as nashi or P. calleryana selections.
P. ussuriensis blooms in early-to-mid-spring and has slightly larger flowers than P. calleryana. The flowers are fœtid when grown in large numbers, but in the average streetscape, the odour is not noticeable.
This pear is probably too large for restricted areas, and many of the P. calleryana cultivars are better-suited for planting on narrow nature strips.
Typical mature height: 12-13m
Useful in: streetscapes, parks, display
Sites for best growth: organic soils, irrigated