A South African Gum. 837 



" Witli ten parts of cold water the gum formed a pale-coloured 

 jelly, wluch was fairly clean and transparent and practically without 

 odour or taste. On heating with water, the gum readily dissolved 

 and furnished a permanent homog-eneous solution. A 10 per cent, 

 solution obtained in this way was, after filtration from insoluble 

 matter, a brownish, slightly cloudy liquid with a viscosity of 83. T, as 

 •compared with 1 for water and 7.0 for a 10 per cent, solution of 

 "Gum Acacia made under the same conditions. The solution possessed 

 fair adhesive power. 



" Commercial Valuation. — Samples of the material were 

 forwarded for valuation to brokers and merchants in London, who 

 did not consider it likely that the gum would be saleable under 

 present conditions except at a very low price. Both firms, however, 

 suggested that a trial shipment of the gum might be forwarded in 

 order to test the market. 



"Remarks. — This gum is superior in quality to previous samples 

 of Combretum Gum received at the Imperial Institute from other 

 sources, being pale in colour and easily rendered soluble by heating 

 with water. The solution is also of fair adhesive power. As stated 

 above, it is doubtful whether the gum would be saleable at the present 

 time in the United Kingdom at a remunerative price, but in order 

 To ascertain this definitely a small consignment of a few cwt. might 

 be forwarded to the Imperial Institute so that further inquiries and 

 technical trials can de made." 



Descriptio>'. 



Comhretum e ry thro phy Hum, Burch., a tree 15.20 feet high, or 

 bush 8-10 feet high. Branches opposite, greyish, smooth; branchlets 

 densely pubescent. Leaves opposite or sub-opposite, 4.5-7 cm. long, 

 1.5-2.5 cm. broad, elliptic or elliptic-lanceolate, shortly acuminate, 

 acute, narrowed at the base, pubescent above and beneath. Inflor- 

 escence axillary, more or less globose, on tomentose peduncles up to 

 2 cm. long. Pedicels and receptacle tomentose. Petals spathulate. 

 Fruit 1.3 cm. long, 1.2 cm. broad, 4-winged. 



This tree, locally known as " Rodeblad Vaderlands Wilg," or 

 Bosveld Wilg," is found in the Transvaal, East Griqualand, and 

 Xatal. It grows xdentifully in the valley of the Aapies Hiver in the 

 neighbourhood of Pretoria, and produces fruit freely. The smaller 

 trees or bushes growing away from the river " gum " more copiously 

 than the taller trees on the river bank. In the Fountains Valley, 

 near Pretoria, three natives gathered 5| lb. of gum in 3^ hours. 



The fruits are often infected with a grub, but sound fruits 

 germinate readily, and at present no difficulty can be foreseen in 

 establishing a plantation of this Combretum in suitable localities. 



Samples of the gum and specimens of the tree yielding it may 

 be seen at the Division of Botany, Pretoria, and any further informa- 

 tion which the Division may receive regarding this gum may be had 

 on application to the Chief, Division of Botany, P.O. Box 994, 

 Pretoria . 



