8 BULLETIN 706, U. S. DEPAETMENT OF AGRICULTURE. 



TANNIN CONTENT OF AMERICAN SUMAC. 



The leaves and leaf stems together of the three most important 

 American sumacs — dwarf, white, and staghorn — when air-dried, 

 contain approximately the same amount of tannin — that is, from 25 

 to 35 per cent.^ The leaves of fragrant sumac are said to contain 13 

 per cent tannin, of American smoke- tree* 21 per cent, and of coral 

 sumac S per cent. Usually the quantity of tamiin appears to be 

 somewhat greater later in the season than in June and early July. 

 The leaves contain the highest percentage of tannin after they are 

 fully grown and before they begin to turn yellow or red. 



Analyses made in the Leather and Paper Laboratory of the Bureau 

 of Chemistry of various samples of sumac gathered in Virginia, West 

 Virginia, Maryland, and Pennsylvania gave the following results: 



Table 4. — Tannin content of samples of dwarf ^ white, and staghorn sumac. 



Species. 



Tannin in leaves and leaf 

 stems. 



Tannin in stalks. 



Average. 



Maxi- 

 mum. 



Mini- 

 mum. 



Average. 



Maxi- 

 mum. 



Mini- 

 mum. 



Dwarf 



Per cent. 

 28.95 

 25. 14 

 27.66 



Per cent. 

 35.03 

 28.08 

 30.59 



Per cent. 

 19.46 

 21.35 

 21.53 



I er cent. 



7.77 

 6.84 

 7.07 



Per cent. 

 9.94 

 7.30 

 8.09 



Per cent. 

 5.09 



White... 



6.19 





6.45 











Dwarf sumac, it will be seen, contains somewhat more tannin than 

 staghorn or white sumac. This bears out in a general way the state- 

 ment of buyers in eastern Virginia, though this difference is of itself 

 not great enough to justify the refusal of the white. The sumac 

 samples analyzed were found to average 73.3 per cent leaves and 

 leaf stems and 26.7 per cent stalks. The vari- .ion, however, was 

 marked, extending, in the case of the leaves a ^ leaf stems, from 

 54 to 89 per cent, and, for the stalks, from 11 ±6 per cent. The 

 large proportion ' of stalks indicated by the percentage last given 

 should never be permitted. Gatherers must be careful to break the 

 stalk close to the lowest leaf stem, and not to gather the long stalk 

 bare of leaves. If the stalks are broken close to the leaf stems, the 

 sumac will usually meet the buyers' demands. Dealers and extract 

 makers very properly insist that the sumac as delivered shall not 

 contain on an average more than 25 per cent of stalks. 



The portions of the plant usually considered of value for tanning 

 and dyeing purposes are the leaves and leaf stems, although, as 

 shown in Table 4, the stalks contain from 5 to 10 per cent tannin, an 

 amount entirely too large to discard after the trouble and expense 

 of collecting and hauling to market has been incurred. This tannin 

 should be recovered, as an extract could be made from the stalks 



1 These figures apply more particularly to Virginia, West Virginia, Maryland, and Pennsylvania sumacs. 



