HOWARD AND HOWARD. 31 



than the branches. The stems and branches are supple but not 

 very rigid, and the plant is lusty rather than erect and has a 

 tendency to sprawl. 



The stems are retted in tlie same manner as those of H. can- 

 nabinus. The fibres are silky and fine, but apparently not so strong 

 as those of H. cannabinus ; the breaking strain of the latter is 

 given by Wiesner' as 115 whereas that of H. Sabdariffa is 

 only 89. 



The following description of the fibre is taken from Dodge's 

 Descriptive Catalogue of the useful Fibre plants of the world. 



" A superb sample of this fibre was shown in the exhibit of 

 British Guiana, W. C. E., 1893, which was accompanied by the 

 stalks some 10 feet high, as straight and clean as jute stalks. 



The fibre was equal, if not superior, to nuich of the jute which 

 comes to this country. In my examination for award it was given 

 the following rating : Length, 90 points ; strength, 75 points ; 

 colour 80 points; average, 81-6." 



Most of the descriptions and statements concerning H. Sah- 

 darifja or Roselle refer to a plant with red stems and red calyces. 

 In a few accounts mentioned is made of a variety with a white calyx 

 but no description is given. It is sometimes said to be less acid 

 than the red variety. No other forms are referred to in the liter- 

 ature. We have at Piisa isolated not only the red and the white 

 varieties but two intermediate forms. These are partly red but 

 in each the localization of the colour is different. 



2. Pollination and natural cross-fertilization. 

 This species forms a striking contrast to H. cannabinus in 

 the entire absence of natural cross-fertilization. Three varieties 

 of Rozelle have been grown next to next at Piisa for four years and 

 not a single instance of natural crossing has been observed. Seed 

 from plants growing near the edges of the plots where the branches 

 of two varieties interlaced was purposely chosen on two occasions 



J Wiesner 1. c 



