March 1908.] 



199 



Saps and Exudations. 



dark variety also exists. The leaves 

 of M. dichotoma are tri- or quinque- 

 partite, and only in the seedlings are 

 they more or less peltate. Indentations 

 more or less lyrate in form soon 

 appear at the tip of the leaf, such as 

 never appear in the much larger leaves 

 of M. glaziovii- Besides other distinc- 

 tions, the large elongated seeds are 

 especially noteworthy. 

 The area of distribution of this rubber 



Slant is confined to South East Bahia 

 etween 12£ and 14| degrees south 

 latitude, where it stretches from the 

 banks of the Rio Paraguassu to half 

 way down the Rio das Coutas. The 

 plant is sometimes called Manitoba von 

 Jequie, after the town of Jequie situated 

 in this region, which is the central 

 market for the rubber produced from 

 this plant. 



Here it grows in the true Catinga," and 

 is especially abundant on the mountain 

 spurs which may be called the mountain 

 Catinga. The more park-like regions, 

 where individual large trees stand 

 scattered, is avoided £by M dichotoma, 

 which prefers a rather more thickly 

 wooded Catinga. It develops best on a 

 red loamy soil and is less frequently to 

 be found on a sandy substratum. With- 

 in a few miles of Porto Alegre on the 

 Rio das Contas, a central station for the 

 production of rubber for this species of 

 Manihot, I have seen mountain spurs 

 covered so thickly with this tree that it 

 made up almost half the total forest. 

 The caoutchouc obtained annually from 

 M. dichotoma in the wild state may be 

 reckoned at 400 to 500 tons at the present 

 time. This does not include plantations, 

 for the discovery of this rubber tree 

 only took place in 1901, and the earliest 

 planted trees are only just coming into 

 condition for tapping. 



Manihot Heptaphylla, Ule. 

 The species of Manicoba which yields 

 most of the rubber from across the Rio 

 Sao Francisco is quite different in 

 appearance. This species forms only 

 dwarf trees with short stems and wide 

 leafy crowns di- or tii-chotomously 

 branched. The M. heptaphylla grows to 

 a height of 2 to 8 metres and has a black- 

 ish bt own bark ; the young twigs and 

 leaf-stalks are a fine purple colour ; the 

 leaves are dark green and usually seven- 

 lobed. The fruits are rounded and not 

 angular, the seeds are round like those 

 of M. glaziovii, but larger and paler than 

 the latter. 



Manihot heptaphylla grows exclusively 

 on the right bank of the Rio Sao Fran- 

 cisco, between 9£ and 12^ degrees of 



* Deciduous forest, dropping its leaves in the 

 dry season.— Ed. 



south latitude, especially in the moun- 

 tains of the district such as the Serra do 

 Encaibro, Serra do Tombador, Serra do 

 Assurua and others. It is sometimes to 

 be found within a few miles of the right 

 bank of the river, but I have never been 

 able to detect its presence on the left 

 bank, The town of Sentese on the Rio 

 Sao Francisco is noteworthy at the point 

 of entry to the centre of this rubber 

 district. I have only been able to ob- 

 serve the wild growth in a limited region 

 lying in the Sena do Sao Iquazio near 

 the town of Chique-Chique. The spe- 

 cies grows there among sandstone rocks 

 together with other trees, and Manicoba 

 and Mangaberia are sometimes to be 

 found not far from one another. There, 

 too, the production of caoutchouc up to 

 the present time may be put at 500 

 tons a year. 



Manihot Piauhyensis, Ule. 



This species comes near the preceding 

 one in general characters. It forms 

 somewhat lower trees of 2—5 m. in 

 height and has 5-lobed leaves with wide 

 apices. The inflorescences are longer 

 and the fruits angular or winged. The 

 seeds of M. heptaphylla and M. piauhy- 

 ensis are scarcely to be distinguished. 

 The area of distribution of M- piauhy- 

 ensis stretches on the south-east of 

 Piauhy along the boundary of Bahia 

 from ahout 8 to 10 degrees of south 

 latitude. There it grows in the lower 

 mountain spurs, which stretch as far as 

 the South of Ceara. It is to be supposed 

 that this Manicoba occasionally appears 

 in Bahia a, few miles from the left bank 

 of the Rio Sao Francisco, but I have not 

 been able to obtain definite proof of its 

 preseuce there. I have been able to 

 observe M. piauhyensis in one of its 

 chief areas of distribution and at a few 

 of the central stations of the rubber 

 industry. It grows here on sandstone 

 mountains in a formation to which I 

 have given the name of mountain- shrubs 

 of the dry North. A wide area is here 

 covered with shrubs and trees a few 

 metres in height, and among them are 

 found the small trees of /!/. piauhyensis. 

 They are to be distinguished from the 

 surrounding vegetation by their fresh 

 brilliant green colour. Only scattered 

 individuals are to be seeu among the 

 actual rocks, and they seem to grow 

 best on a sandy soil. They often spring 

 up in abundance in places where the 

 woods have been destroyed by burning. 



There is considerable difficulty in 

 estimating the quantity of rubber 

 obtained here, because it leaves the 

 country by several routes ; part is 

 carried to Theresina through Piauhy 

 itself, part goes to Pernambuco, and 

 the greatest quantity of all to Bahia, 



