Pyrus boissieriana is best treated as a subspecies of Pyrus cordata (as Pyrus cordata subsp. boissieriana (Buhse) Uğurlu & Dönmez) according to Zübeyde Uğurlu Aydin & Ali Aslan Dönmez; 'Taxonomic and nomenclatural contributions to Pyrus L. (Rosaceae) from Turkey'; Turk J Bot (2015) 39: 841-849.
This species is sometimes treated as a synonym of Pyrus communis[
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[
Pyrus cordata boissieriana (Buhse) Uğurlu & Dönmez
Pyrus boissieriana is an unarmed to spiny, deciduous tree with a wide, irregular crown; it can grow 5 - 15 metres tall, though sometimes it remains a shrub. The plant often freely produces suckers[
Te plant is cultivated in the Caucasus and Turkmenia as a rootstock for the cultivated pear[
]. It is deserving of attention as an ornamental.
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[
Central and western Asia - Azerbaijan, Turkmenistan, Iran
Dry slopes; at elevations from 600 - 1,200 metres[
]. Found at elevations up to 2,400 metres[
|Other Uses Rating||
Pyrus boissieriana is very cold-hardy, tolerating temperatures down to at least -20°c when dormant[
Species in this genus generally prefer a good well-drained loam in full sun[
]. They usually grow well in heavy clay soils. They tolerate light shade but do not fruit so well in such a position, tolerate atmospheric pollution, excessive moisture and a range of soil types so long as they are moderately fertile[
]. Established plants are generally drought tolerant[
The plant is deserving of attention as an ornamental[
The subglobose fruits are reddish-brown with white spots, around 10 - 15mm in diameter[
A very droughtresistant species, it is valuable for breeding programms with the common pear (Pyrus communis) and also as a rootstock for grafting in more arid regions, though it gives rise to abundant root suckers[
Seedlings and root suckers are grown as drought resistant rootstocks for pears[
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.