Sorbus is treated here in the broad sense, including the subgenera Aria and Torminaria. However, these two subgenera are likely to be recognized at generic rank, based on flower and fruit characters, once molecular studies can consistently resolve their placement within the Pyrinae, overcoming current difficulties with interfertility, reticulate relationships, rapid radiation, and small samples[
The taxonomy of Sorbus is complicated by apomixis, polyploidy, and hybridization among sections and genera, especially in Eurasia. Sorbus hybridizes with several other genera in the tribe Maleae, including Amelanchier (×Amelasorbus Rehder); Crataegus (×Crataegosorbus Makino); Aronia (×Sorbaronia C. K. Schneider); Cotoneaster (×Sorbocotoneaster Pojarkova); Pyrus (×Sorbopyrus C. K. Schneider), and Malus (×Tormimalus Holub [= Sorbus subg. Torminaria × Malus])[
Aria thibetica (Cardot) H.Ohashi & Iketani
Pyrus thibetica Cardot
Sorbus atrosanguinea T.T.Yu & H.T.Tsai
Sorbus wardii Merr.
Sorbus thibetica is a deciduous tree, usually growing 7 - 10 metres tall, sometimes to 15 metres, but occasionally more shrub-like[
The plant is harvested from the wild for local use as a food and source of materials.
Although no specific information has been seen, the seed, and other parts of the plant, is 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[
E. Asia - E. Himalayas - China (Thibet, Yunnan), Bhutan and northern Myanmar
Dense forests on slopes or in valleys, rocky slopes, streambanks and shrubby thickets; at elevations from 2,400 - 3,800 metres[
|Other Uses Rating||
Sorbus thibetica is a moderately cold-hardy tree, tolerating temperatures down to around -20°c when dormant
Succeeds in most reasonably good soils in an open sunny position[
]. Tolerates light shade[
], though it fruits better in a sunny position[
Plants are susceptible to fireblight[
Closely related to Sorbus cuspidata[
Fruit - raw or cooked. Very nice raw when it is fully ripe, preferably picked after a frost[
]. At this stage it has a mealy texture and a mild-flavoured slightly sweet fruit. The fruit can also be bletted. This involves storing the fruit in a cool dry place until it is almost but not quite going rotten. At this stage the fruit has a delicious taste, somewhat like a luscious tropical fruit. The scarlet, ovoid or obovoid fruit is 9 - 15mm x 7 - 13mm[
We have no specific information for this species, but the wood of Sorbus species in general is hard, heavy, and fine-grained, and is suitable for making furniture or small, carved articles[
Seed - best sown as soon as it is ripe in a cold frame[
]. If you have sufficient seed it can be sown in an outdoor seedbed[
]. Stored seed germinates better if given 2 weeks warm then 14 - 16 weeks cold stratification[
], so sow it as early in the year as possible. Prick out the seedlings into individual pots when they are large enough to handle. Seedlings are very slow to put on top-growth for their first year or two[
], but they are busy building up a good root system. It is best to keep them in pots in a cold frame for their first winter and then plant them out into their permanent positions in late spring.