152 



llELATION BETWEEN CLIMATE AND VEGETATION 



and distant from Crato in a westerly direction nearly 500 miles. 

 The greater part of the journey lay through a country which in 

 the dry season becomes quite a desert, but which in the rainy 

 season is verdant enough, the Catinga forests being then covered 

 both with leaves and flowers, and the annual grasses, and the 

 perennial herbaceous plants, which during the drought were ap- 

 parently destroyed, covering the soil with a green carpet. At 

 about two leagues to the west of Crato we entered upon the 

 great Serra of which the Serra de Araripe is a branch. This is 

 called by the native Indians Ibiapaha, and by the Brazilians 

 Serra Vermelha. On the top it is perfectly level, and between 

 thii-ty and forty miles in breadth. The first half of it is very 

 similar to the Serra de Araripe, that is, thinly covered with trees 

 of moderate size, with an abundance of low shrubs and herbaceous 

 plants ; but the west half is very thickly wooded with small 

 trees, large tracts of which are every season burned to allow of 

 a more abundant supply of herbage for the cattle and horses 

 which are sent to pasture on it during the dry season. The 

 Serra does not reach the level country to the westward till about 

 twenty leagues from the western boundary of the Taholeira, 

 gradually decreasing by long undulating or flat sandy tracts. 

 The last of these is a little beyond a place called Varze da Vaca. 

 The low thin forests which cover these tracts are Catingas ; 

 but in the flat tracts the trees are fewer, and during the rainy 

 peason afford abundance of herbage, on which large herds of 

 cattle feed. Although the general vegetation was somewhat 

 similar to that around Crato, 1 found much that was new to me. 

 Among the trees I may mention a large one called Cedra by 

 the inhabitants, the wood of which is in much request for house- 

 hold purposes. It smells strongly of the common cedar, but be- 

 longs to the natural order Meliacece. Another, which I did not 

 meet with in flower, is called JBrduna, and the wood, wliich is 

 very hard, is much used in mill-work. It belongs to the natural 

 order Leguminosce. A Spondias {S. hcherosa, Arrud.) is also 

 common, and produces a fruit which is very much esteemed. 

 There were also some fine large Mimosece. Some of the flower- 

 ing shrubs were very fine, the violaceous Allarnanda being not 

 the least common. The others were species of Coutarea, He- 

 ticteres, Cordla, Cd'salpinia, a scandent shrubby species of 

 Angelonia {A. bracteata^ Benth.), &c. The herbaceous plants 

 consisted of various species of Cleome, Physostemon, a Loasa {L. 

 rupestris, Gardn.), sex era.] Hi/pHds, a Preslea, Angelonia arguta, 

 Benth., with A. serrata, Benth., and A. piibescens, Benth., a 

 beautiful little speciesof£'c7<?7e,?, about six inches high, with very 

 narrow leaves, producing several flowers, similar both in appear- 

 ance and colour to those of Phlox verna. It has large black 



