448 BOTANICAL GAZETTE [may 



A new rubber. — Hall and Goodspeed, 10 in connection with the war 

 demand, have investigated a possible native source of rubber, studying 

 especially Chrysothamnus. They found rubber of high grade in C. nauseosus, 

 and adopted the name "chrysil" for this particular kind or rubber. This 

 species includes 22 recognized varieties, which have been taxonomically 

 presented by Hall. 11 Of these varieties, 12 were examined and all found to 

 contain rubber. The shrub grows readily from seed and matures in 6-8 years. 

 The largest stands occur in Colorado, Nevada, and Utah; and it is estimated 

 that the total amount of rubber present in wild shrub is over 300,000,000 lbs. 



Chrysil is not a latex rubber, but occurs in individual cells. The results 

 of 180 -chemical analyses and 80 microscopical examinations are tabulated. 

 The rubber occurs in the plants in greatest abundance about the soil line, 

 being present in the root in only the upper parts, and occurring in small 

 amounts in young twigs and leaves. The best varieties for rubber are those 

 growing in alkaline soils, so that the culture of this rubber-yielding plant could 

 be developed extensively in alkaline regions unsuitable for other crop plants. 



The authors 12 also give an account of the occurrence of rubber in other 

 species of Chrysothamnus and in Haplopappus. They also append a long 

 list of species, chiefly Compositae, in which no rubber was found. — J. M. C. 



Philippine bamboos. — In a recent bulletin Brown and Fischer 13 have 

 presented much interesting data regarding the taxonomy, ecology, and 

 economic value of Philippine bamboos. Nine genera, including 30 species, 

 17 erect and 13 of climbing habit, are described, and a key for identification is 

 provided. Planting and harvesting methods are discussed, and some data 

 regarding market prices given; but of much more interest to ecologists is a 

 series of accurate growth records extending over a period of 20 weeks. Growth 

 rates of 2 m. per week are not uncommon, and several shoots showed a weekly 

 growth in excess of 3 m. — Geo. D. Fuller. 



Salix. — Schneider, 1 * in continuation of his studies of American willows, 

 has discussed the section Adenophy llae , recognizing 8 species, one of which 

 (from California) is described as new. The discussions and descriptions are 

 very full, and are accompanied, by complete citations of collections, so that 

 taxonomists will be at no loss as to the plants referred to. — J. M. C. 



10 Hall, H. M., and Goodspeed, T. H., Chrysil, a new rubber from Chrysothamnus 

 nauseosus. Univ. Calif. Publ. Bot. 7:183-264. pis. 18-20. figs. 6. 1919- 



11 Hall, H. M., Chrysothamnus nauseosus and its varieties. Idem HiS^^ 1 - 



1919. 



Goodspeed 



American shrubs. Idem 7:265-278. figs. 2. 1919. 



* Brown, Wm. H., and Fischer, A. F., Philippine bamboos. PX Dept. Agric 

 and Nat. Res., Bur. For. Bull. 15: pp. 32. pis. 33. 1918. 



turn 



American 



