200 ON SOME N.S.W. TAN-SUJ3STANCES. 



scattered, linear or almost linear-lanceolate, obtuse or tapering into 

 a recurved point, rather thick but flat, 2 to -1- or even 5 inches 

 long, contracted into a short petiole." They yield a bronze-green 

 powder. 



Extract. — Yields 42-92 per cent, to water at 100° C. Colour 

 of solution light orange-brown, and slightly fluorescent. Becomes 

 turbid when moderately concentrated. Colour of moist residue 

 dark bronze-green inclining to brown. 



Tannic acid — 9*705 per cent. 



43. Polygonum plebejum, R. Br., N.O. Polygonaceaa, B. Fl. v., 2G7. 

 Found in all the colonies except AVestern Australia and 



Tasmania. It is not, however, endemic in Australia, as 



it is to be found in Tropical Asia and Africa. 

 Locality whence this particular specimen was obtained — 



Quiedong, near Delegate. 

 Geological Formation — Limestone. 

 Whole plant examined except the root. It was for the most 



part in fruit. 

 Collected 7th April, 1887. Analysed 19th August to 29th 



September, 1887. 



The following description of P. plebejum is taken from the 

 " Flora Australiensis," and will be useful to refer to here : — "A 

 much-branched prostrate annual, rarely about 1 foot long, glabrous 

 or the branches slightly hoary. Leaves linear, narrow-oblong or 

 slightly spathulate, rarely above J" long. Stipules short, silvery, 

 and ragged at the edges. Flowers very small, in clusters of 2 to 

 5 in the axils of most of the leaves. Fruiting perianth under 1 

 line long, the segments green, with a narrow white edge. Nuts 

 triangular, very smooth and shining." 



This genus contains 150 species according to the "Genera 

 Plantarum " of Bentham and Hooker. Of these 1 1 are found in 

 Australia, and some of these are endemic. 



I chose P. plebejum for the purposes of the present examination 

 because I had a most convenient opportunity of obtaining a 

 quantity of it, but various species are common in swampy country 

 throughout the Colony, and it is very probable that at an early 

 date I may report on the tanning power of those species found 

 about Sydney. 



Most books which refer to Tan-substances take cognizance of 

 species of Polygonum, which are more or less astringent. Perhaps 

 the best known species is P. Bistort a, Linn., figured in Bentley 

 and Trimen's " Medicinal Plants," which has a very astringent 





