Document Type : Research Paper
Authors
1 Research Institute of Forests and Rangelands
2 -
Abstract
Acording to results of the investigation, the manna know as Shir-khest exudes from the branches of two species of cotoneaster (Rosaceae).
C. nummularia Fisch & Mey and C. nummularioides Pojark
Atraphaxis spinosa L. (Polygonaceae) has no manna in Tehran. Province (even in other places.)
The manna of Shir-khesht collected from the shrubs in kushk-E-BALA village altitude 1900-2200 m (31 Km far from karadj in chalus road.) Shrubs in this area have been attacked by insect of scolytus rugulosus Mull (col. Scolytidae., Scolytinae.) and in other places which also have shrubs but without insect and larva so have no exudation. Larvae of this insect makes tunnel under the skin and destroy cambium then from these sites manna exudes. Exudation concern to humidity and tempereture of the sites, in the end of July to early August the difference of Maximums and Minimus temperatures are significant and high over twenty degree centigrade and in this period precipitation comes near Zero. Shir-khist occurs in small yellowish-white granules about the size of millet seed. During July and early August the branches of the cotoneaster become covered with the exudation, after few days become hard, collect and mixe with flour. it is valued chiefly as medicinal product (pectoral, purgotive.).
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