19S 



f March 1908. 



GUMS, RESINS, SAPS AND EXUDATIONS. 



NEW SPECTES OP MANIHOT AND 

 THEIR IMPORTANCE. 

 By Dr. Ule. 

 [translated by r. h. lock.] 



No. 10 of the " Pflanzer" for August of 

 the present year contained brief notices 

 of three new species of Manihot, which, 

 until more exactly determined, may be 

 designated Jequie Manihot, Piauhy 

 Manihot, and Rio Sao Francisco Manihot. 

 The appearance of Dr. Ule's communica- 

 tion to the Bahia-Indiarubber Syndicate 

 of Leipzig now enables us to give a 

 more complete account of the new rubber 

 trees ; and the interest and importance 

 of the contents of this communication 

 justifies our reproducing it in full-* 

 The following is Dr. Ule's paper :— 



In his paper " Die Kautschukpflanzen, 

 eine Wirtschafts-geographische Studie" 

 in the supplement to the "Tropen- 

 pflanzer " for 1905 Peter Reintgen states : 



"Until four years ago Manihot glaziovii 

 .was reckoned the only rubber-yielding 

 species of its genus. In 1901, however, 

 Prof. Loefgren, Director of Botanic 

 Garden at Sao Paulo, discovered that a 

 second species (Manihot violacea Mull 

 Arg.) was by no means inferior in quality 

 to the familiar Ceara rubber." 



This new rubber plant has not, how- 

 ever acquired any importance on account 

 of its being an herbaceous plant from 

 which it does not pay to extract the 

 rubber either in the wild condition or in 

 cultivation. But. as so often happens in 

 the case of problems connected with 

 rubber, small facts may lead to important 

 discoveries. 



For some years past attention has 

 been drawn to the steadily increasing 

 output of rubber by the Brazilian State 

 of Bahia, and orders were issued by the 

 German Government to its Consuls to 

 inquire into the cause of this increase. 

 And it was found to depend upon the 

 output, not of Hancornia speciosa, the 

 Mangabeira, but of Manicoba, hitherto 

 regarded as being simply Manihot 

 glaziovii. 



* The attention already aroused by these new 

 Manihot species is shown by the facts that the 

 seed brought by Dr. Ule from Brazil has been sent 

 by the Central Botanical Institute for the Colonies 

 to the Government Stations in the Colonies for ex- 

 periment, that the Committee of Colonial Industries 

 has brought seed from Bahia and distributed it to 

 the various companies, and that several Rubber 

 Planting Companies have already made large 

 purchases of seed on their own initiative. 



During my journey to Bahia in the 

 summer of 190(5, however, on behalf of 

 the Bahia Rubber Syndicate of Leipzig, 

 I examined more closely into the 

 Caoutchouc-districts of Manihot, and it 

 became clear that several species of Mani- 

 hot have to be reckoned with. Several 

 journeys into the interior of Bahia have 

 clearly established this opinion, and I 

 have now arrived at results of consider- 

 able interest. 



My observations show that there are 

 two different rubber-producing species 

 of Manihot in the interior of Bahia. One 

 of these grows upon the mountains upon 

 the right bank of the Rio Sao Francisco, 

 the other occurs only at a considerable 

 distance from the left bank, and is much 

 more abundant in the neighbouring 

 State of Piauhy. The latter appears to 

 be the better species of the two. 



In the tree-steppes of the Serra do 

 Sao Ignazio the Mangabeira is frequent, 

 often occurring in fine thickets. A 

 species of Manicoba is also sometimes to 

 be found in the immediate neighbourhood 

 of this rubber plant, but more usually it 

 grows in the rock-formation, thus demon- 

 strating its claim to be regarded as a 

 true mountain plant. 



The Manicoba Species of Manihot. 



The number of species of the genus 

 Manihot hitherto described is 82, of 

 which number 72 are found in Brazil. In 

 addition to these there are seven newly 

 proposed by myself including two from 

 the Amazon, and in the herbarium there 

 still lie numerous undescribed species, so 

 that the number will soon exceed 100. 



The species show numerous differences 

 in the form of the leaves and in the shape 

 of the flowers and fruit, and they often 

 differ in habit as well. A few are small, 

 often prostrate herbs, others are under- 

 shrubs, whilst shrubs and trees are also 

 found. It is the latter group which 

 requires consideration as yielding india- 

 rubber, and suchtreesare called Manicoba 

 by the natives. The Manicoba species 

 belong to different divisions of the genus 

 Manihot and exhibit differences both in 

 their structure and in their caoutchouc. 

 Manihot Dichotoma, Ule. 



This species does not grow into so tall 

 a tree as Manihot glaziovii, and varies 

 between 5 and 12 metres in height ; the 

 growth of the crown is, moreover, much 

 more compact and usually thickly 

 branched in a dichotomous fashion. The 

 stem also is not so thick, the bark is 

 thinner and usually paler, although a 



