290 RELATION BETWEEN CLIMATE AND VEGETATION 



fieally lighter than the water, floats upon the surface of the 

 shallows, its long fibrous roots only reaching to the mud at the 

 bottom. Along the borders of these lakes grew several large 

 Polygonums^ one of which has stout spikes of greenish-white 

 flowers, and another considerably resembles our P. ampJdbium : 

 there also abound Pontederia pajiiculata, Hydrolea spinosa, 

 and a late species of Ammannia. Several parts are covered with 

 a floating turf, consisting principally of different Sedges; and 

 when this does not exist, Jussicea nutans, Humb., throws along 

 the surface of the water its long floating branches, which are 

 upborne by numerous small white cylindrical bladders attached 

 to the lower side ; the flowers are white, and about the size of 

 those of Ranunculus aquaticus , to which, at a distance, the plant 

 bears considerable resemblance. Mingled with the Jussicea 

 there exist vast quantities of a large species of Azolla, and the 

 curious Pistia Stratiotes. In the wood itself grew many species 

 q{ Myrtle-blooms, Anonads, Cinchonads, a few Melastomads, and 

 great abundance of the Cashew-nut tree ; also several species of 

 Coccoloba, a Vismea, Zizyphus Gardneri, Reiss., together with 

 two or three species of Byrsonima. There were also many 

 bushes of a species oi Eschweilera, which when covered, as was 

 then the case, with its curious pale yellow flowers, were beautiful 

 objects. Twining among these and the other trees, I observed 

 some fine plants of a Gomphia, its large panicles of golden 

 blossoms harmonizing most agreeably with the shining dark- 

 green foliage ; likewise a species of Trigonia, and, on the banks 

 of the river, an Inga, and a Combretum with large clusters of 

 small pale-yellow highly-scented flowers. On first entering this 

 wood I was particularly struck by the different aspect it presented 

 to those of the same kind about Rio. Here every thing be- 

 tokened a drier atmosphere and a more arid soil. No Ferns, 

 Begonias, Peppers, or Orchids, were to be seen. On the 

 stems and branches of the larger trees a few Bromeliads and 

 Arads alone existed. 



About 18 miles to the west of Pernambuco there exists a 

 small German colony at a place called Catuca, which, being sur- 

 rounded by virgin forest, I was desirous to visit. The first part 

 of the journey was through a flat sandy country, partly planted 

 with Mandioc, and partly in a wild state. The last hour's ride 

 was through a forest, the under-wood of which consisted chiefly 

 of Melastomads, Myrtle-blooms, and Cinchonads. The finest 

 plant collected here was an Acanthaceous climber with large 

 scarlet flowers. 



On leaving this wooded tract, the cleared valley in which 

 the colony is situated was gained. A young friend who ac- 

 companied me being desirous of having a day's hunting with 



