Pyrus ussuriensis var. ovoidea Rehder (J. Arnold Arbor. 2: 60. 1920) is, in fact, a cultivar of Pyrus ussuriensis. It is characterized by its ovoid, subglobose, or ellipsoid fruit, longer fruiting pedicels (2-4 cm) and tomentose leaves and corymb[].
In spite of their wide geographic distribution, the various species in the genus Pyrus are intercrossable without major incompatibility barriers. Also, the high morphological diversity and the lack of distinguishing characters among the species have been reported. Therefore, the classification of species in this genus is problematic and often confusing, giving different populations designated as different species by some authors. It is likely that, when the genus is reviewed, there will be several changes to the nomenclature[].

Common Name: Harbin Pear

General Information

Pyrus ussuriensis is a spiny, deciduous tree with a broadly pyramidal or oval, dense crown; it can grow 10 - 15 metres tall[, , ].
The plant is harvested from the wild for local use as a food and source of materials. The tree is cultivated, especially in northern China, and the fruits are sold in Manchurian markets as 'li.' The plant is also often used as a rootstock for the cultivated pears.

Known Hazards

Although no specific information has been seen for this plant, the seed of many species in the family Rosaceae are likely to contain cyanogenic glycosides. When injested, these compounds break down in the digestive tract to release cyanide. Used in small quantities in both traditional and conventional medicine, this exceedingly poisonous compound has been shown to stimulate respiration, improve digestion, and promote a sense of well-being[]. It is also claimed by some to be of benefit in the treatment of cancer - though this claim has been largely refuted.
In larger concentrations, however, cyanide can cause gasping, weakness, excitement, pupil dilation, spasms, convulsions, coma and respiratory failure leading to death[].
The levels of toxin can be detected by the level of bitterness:- sweet almonds, for example, contain only very low levels of it and are safe to eat in quantity, whilst bitter almonds (which are used as a flavouring in foods such as marzipan) contain much higher levels and should only be eaten in very small quantities. Great caution should be employed if the taste is moderately to very bitter[].

Botanical References

, ,

Range

E. Asia - Russian Far East, northern China, Japan, Korea

Habitat

Forests and river valleys in lower mountain zones[].

Properties

Edibility Rating
Other Uses Rating
Habit	Deciduous Tree
Height	12.00 m
Pollinators	Insects
Cultivation Status	Cultivated, Wild

Cultivation Details

Pyrus ussuriensis is a very cold-hardy plant, tolerating temperatures down to at least -20°c when dormant[].
Prefers a good well-drained loam in full sun[]. Grows well in heavy clay soils. Tolerates light shade but does not fruit so well in such a position. Tolerates atmospheric pollution, excessive moisture and a range of soil types if they are moderately fertile[]. Established plants are drought tolerant[].
This species is a parent of the cultivated Asian pears[].
This species varies in size, shape, colour, and taste of fruit, on the basis of which Skvortzov has described several varieties which may be of importance for selection[].
This species has more than 150 cultivated forms, the fruit of which are edible[]. It is commonly cultivated in N, NE, and NW China and also in Siberia[].

Edible Uses

Fruit - raw or cooked[]. Size and quality varies tremendously from tree to tree. Good forms have somewhat dry but pleasantly flavoured fruits up to 4cm in diameter, other forms are less pleasant and often smaller[]. The subglobose fruit is yellowish, often with reddish spots, it can be 15 - 65cm long[, ].
The fruits may be eaten raw or dried; to improve the taste of lower quality forms they are fermented in heaps and then salted[, ].

Medicinal

None known

Other Uses

Used as a rootstock[] for Pyrus pyrifolia culta in Korea[], it is very frost resistant[].
Being very frost -resistant, this species is valuable as stock for grafting for northern horticulture and attention is
being given to this possible use[].
The plant is often used as stock for grafting pear cultivars[].

The dense, heavy wood has the same applications as that of Pyrus communis[].
The following is the information on Pyrus communis wood:-
The reddish-brown wood is fine grained, heavy, hard, tough, durable. It weighs 51lb per cubic foot[]. It is used by cabinet and musical instrument makers and for lathework[, , , , ]. When covered with black varnish it is an excellent ebony substitute[].

Propagation

Seed - best sown in a cold frame as soon as it is ripe in the autumn, it will then usually germinate in mid to late winter. Stored seed requires 8 - 10 weeks cold stratification at 1°c and should be sown as early in the year as possible[]. Temperatures over 15 - 20°c induce a secondary dormancy in the seed[]. Prick out the seedlings into individual pots when they are large enough to handle and grow them on in light shade in a cold frame or greenhouse for their first year. Plant them out in late spring or early summer of the following year.