58 NEW ESCULENTS RECEIVED IN THE 



they are likely to become of interest, the following account of 

 them by M. Decaisne ^Yill pi'ove hiteresting: — 



" The Oca is very extensively cultivated in the temperate parts 

 of Bolivia, where several varieties of it are distinguished. Two 

 are known by the names of Oca hlauca and Oca colorada. The Mu- 

 seum is indebted to M. Bourcier for the latter, which he considers 

 superior in quality to the Oca blauca, although M. Weddell is of 

 a different opinion. The Oca blanca is beginning to appear in 

 our markets ; it is now to be found in most gi-eengrocers' shops, 

 but the slightly acid flavour of the tubers is disagreeable to some 

 persons. This acidity may be converted into a sugary flavour by 

 exposing them to the sun, which converts the acid into saccharine 

 matter. This phenomenon is analogous to what goes on at the 

 ripening of most fruits. The Oca, when treated in this way, loses 

 all trace of acidity and becomes as floury as the best varieties 

 of potatoes. According to M. Weddell the Oca should be exposed 

 to the sun from six to ten days. In Bolivia this operation is 

 performed in woollen bags, which appear to facilitate the con- 

 version of the acid. To obtain this result, the bags should 

 contain no more tubers than are sufficient to form a thin layer 

 within the bag. If the action of the sun is continued for several 

 months the Ocas become of the consistence and sweet taste 

 of dried figs ; they are then called Caul. The Caui is cooked by 

 steam, the tubers being placed on a bed of straw which keeps 

 them from contact with the water over which they are cooked. 

 In Bolivia, and more especially at La Paz, the Oca is cultivated to 

 double the extent of the potatoe. The price is also twice as 

 high as that of the last-named vegetable." — Rev. Hort. 4. ser. 

 vol. 2., p. 383. 



U. Gesnkra esculenta. 



Seeds under this name were received from M. Vilmorin of 

 Paris in the spring of 1853. The leaves proved to be narrowly 

 oblong, about four inches and a half in length, and one inch and 

 three quarters broad, pale green, and soft with pubescence, 

 especially on the under side ; petioles short. The plants did not 

 flower, and died down in the beginning of October ; but in the 

 pot a number of roundish tubers had been formed, about an inch 

 in diameter, of a whitish colour. AVhen boiled, these tubers 

 were somewhat farinaceous, of a transparent bluish white; but 

 had a disagreeable bitter, like that of potatoes which have been 

 partially greened. The seeds were sown and placed in a melon- 



