40 
Rubber Producing Plants, 
Until the recent discovery of “Gnayule” all know 
rubber producing plants* were included m the four Natural 
Orders of Euphorbiace ae, Moraceae, Apocynaceae, and A s- 
cSaceae The addition of “Guayule” (Parthemmn 
araZtatum) and Colorado rubber (Actinella Richardsonn) 
introduces another order, viz. Compositae. An addition to 
Ihe Asdepiadaceae is furnished by a new introduction from 
Angola and Zambesi called Encanda rubber, and described 
as Raphionacme utUis. There are witeous 
Orders of wliicli some genera are said to be lactileious 
plants but of theoretical interest only.f 
The arrangement of the different families of com- 
mercial rubber plants is as follows: t 
Euphorbiaceae : — Hevea, Manihot, Micrandra, Sapium. 
Moraceae: — Ficus, Castilloa. 
A nocunaceae : — Landolphia, Funtumia, Carpodmus, Cti- 
1 tundra, Tabernamontana, Mascarenhasta, Hcincotma 
Forsteronia WiUughbeia, Urceola, Leuconotis, Melo- 
dinus, Parameria, Chonemorpha, Chilocarpus, Dyei a, 
Asclepia'daceae : — C ryptostegia, Baphionacme. 
Com positae : — Partheniutn, Actinella. 
Rubber Sources. 
The world’s output of raw rubber is stated to be as 
follows. 43 ? 000 tons. 
22,000 tons. 
South America (including Mexico) 
Africa 
Eastern and Indo Malaya 
500 tons. 
Total 65,000 tons. 
All of' this output is forest or wild rubber. § From 
South America the bulk of rubberis ar^Ceara 
35 ISzzfailS A SSSJIT) J5li 
Mayan spectl 9 of’Iw« ^tah tamp and tampang) are not 
''^ d A toruwTot™f b Xtation rubber in not included in this estimate. 
