694 



(Jamaica, Burkill)] Affon (Jamaica, Specimen from Hope Bot. 



Oarden in Herb. Kew); Connie Yam (Tobago, Broadivay); 



Yellow Yam (Trinidad, Jamaica, Grenada, Dominica, Antigua, 



Hart, No. 6097, 1896, Herb. Kew) ; Half-a-yam (Barbados, Hart) ; 



Yam a tout ans (Trinidad, Hart)] Yellow or twelve months 



■Guinea Yam {BurUll, I.e.); Igname a feuilles arrondies {Poiret, 

 Lamar cic). 



Old Calabar (Johnson, July 1919, Herb. Kew); S. Pro\inoes, 

 Nigeria (Johnson, No. 7, 1915, Herb. Kew; Burldll, No. 314, 

 1916-17, Herb. Kew — cult. Singapore), Gold Coast and probably 

 widely cultivated in West Africa and also cultivated in the 

 West Indies. 



- The '' Afon Yam " is described as having coarse, yellowdsh- 

 wHte flesh and unless fully ripe the flavour is somewhat bitter; 

 although extensively grown for use by the poorer classes it is 

 not much used by the well-to-do in Trinidad, where the name 

 indicates it as being somewhat of a favourite. Of all the varieties, 

 it is the one which can be had most frequently in and out of 

 season, in fact all the year round (Hart, Bull. Msc. Inf. Roy. Bot. 

 Odns. Trinidad, Oct. 1895, p. 209). The same is said of " Afon '' 

 in Jamaica, where it is said to thrive in hot districts and not so 

 readily afEected by unfavourable climatic conditions as the more 

 delicate '' white yams " (Harris, Bull. Bot. Dept. Agric. Jamaica, 

 Jan. 1906, p. 4). The practice of harvesting the roots of this 

 yam while the plants are kept growing appears to be the same in 

 Trinidad and Jamaica (11. cc). 



Exposure during growth of the tubers causes them to be 

 bitter, and heavy damp soil is said to make the tubers clammy in 



when boiled and anything but palatable ; but when grown 

 in good open soil they are fairly dry and mealy (Harris, I.e.). 



All cultivators seem to be agreed that this j^am has a long 

 vegetative period — up to 12 months. The average jield in 

 grammes during four seasons of growth in Singapore of " Iganyan 

 Alo/' has been found to be 4904, 7544, 1819 and 5856 (Burkill, 

 Gardens Bull. Str. Sett, Sept. 12th, 1919, p. 165) and the weight 

 of tubers from the Department of Agriculture, Old Calabar, 

 received at Kew in Feb, 1920 is given as 12 lb. 6 oz. ('* Akpana ") 

 and 3 lb. 2 oz. (" Efiam "). It is reported that '' Yellow Yams "^ 

 do not keep well and though they may be prepared so that they 

 may last a month, they are not favoured by exporters of yams 

 (Joum. Jamaica Agric. Soc. March 1900; 

 April 28th, 1906, p. 140). 



The African cultivated vanntips; nf x^a 



texture 



Agric. News, Barbados, 



less uncertain as to their origin, but the common forms of D. alata, 

 and D. bulbijera, are in the main the same as those of India, 

 West Indies and in view of a name such as *' Otaheite Potato " 

 {D. bulbifera [sativa]) probably also of the Tropics of both hemi- 

 spheres. There has not been any comprehensive survey of the 

 whole series and though many authors have tackled " Yams " — 

 invariably approacliing the subject with admirable caution — it 



