• REPORT OP THE COMMISSIONER QF AGRICULTURE. 25 



latter class; and even with this limitation great discrimination is nec- 

 essary to select for propagation only those species and varieties that 

 are of special merit and such as promise to be of value to the country. 



The demand for tropical and semi-tropical fruit-bearing plants has 

 been very pressing for several years from the warmer regions of Cali- 

 fornia and Florida. These demands are being met so far as the means 

 of the Department will permit. Observation proves that the climatic 

 conditions necessary for the profitable culture of tropical plants are 

 confined to a very limited area in the United States. Of course there 

 are many tropical plants which produce their crops as annuals, and 

 which can be profitably cultivated over an extensive area — such as 

 cotton — and which only require a comparatively brief tropical season 

 for their maturity. But in the case of ligneous plants which are 

 perennial in their nature, the cold portion of the year, although of 

 short duration, is still sufficiently severe to permanently injure them. 

 The limits, therefore, of climate congenial to the growth of the va- 

 nilla bean, the chocolate plant or cacao, the coca, erythroscylon coca, 

 coffee, cinnamon, nutmeg, pepper, cinchona, &c., are not yet defined. 

 In localities where, owing to a series of congenial seasons, success 

 seemed certain, an unusually cold period has destroyed all hopes ; 

 but this partial success is sufficient to encourage further attempts, 

 although it would seem that such experiences would tend towards a 

 different conclusion. 



With regard to plants of a semi-tropical nature, such as the citrus 

 family, experience proves that, under favorable conditions- of posi- 

 tion and culture, the coldest seasons likely to pertain in orange- 

 growing regions are comparatively harmless to these crops, thus giv- 

 ing the industry a factor of permanency greatly in its favor. 



■ The Department continues to foster industries of this kind by in- 

 troducing new varieties and testing and disseminating the plants. 



BOTANICAL DIVISION. 



During the past year the work of the Botanical Division has been 

 conducted with good success. Large and important additions have 

 been made to the herbarium, which is constantly becoming more val- 

 uable as a representation of the flora of North America. In order to 

 facilitate an acquaintance with the grasses of the country, a distri- 

 bution of typical specimens has been made to twenty or more of the 

 agricultural colleges and experiment stations and other educational 

 institutions. 



The subject of suitable grasses for cultivation in different climates, 

 soils, and conditions is receiving attention from other countries as 

 well as our own, and frequent applications from abroad are received 

 for seeds of our native grasses for the purpose of expei'imental culti- 

 vation. One such application has been received from the govern- 

 ment botanic garden in Upper India, where extensive tracts of saline 



