240 The Principles of Vegetable- Oar dening 



A classification based on botanical kinships or on natu- 

 ral- families. This gives the most perfect scheme, so 

 far as mere classification is concerned, but it does not 

 elucidate principles of cultivation. (3) A classifica- 

 tion based on essential methods of culture. Such a 

 scheme, although necessarily arbitrary in some places, 

 I now propose. In many parts it closely parallels 

 Loudon's. 



Class I. Annual Vegetables. 



Sub -Class I. Crops grown for subterranean parts. 

 Group 1. EooT Crops. 

 Beet, Beta vulgaris. 

 Carrot, Daucus Carota. 

 Parsnip, Pastmaca sativa, 

 Eadish, Baplianus sativus. 

 Salsify, Tragopogon porrif alius. 

 Scorzonera, Scorzonera Hispanica. 

 Turnip and Rutabaga, Brassica. 

 Horse-radish,^ Cochlearia Armoracia. 



Group 2. Tuber Crops. 



Potato, Solanum tuberosum. 

 Sweet Potato, Ipomcea Batatas. 



Group 3. Bulb Crops. 



Onion, Allium Cepa, A. fistulosum. 

 Leek, A. Porrum. 

 Garlic, A. sativum. 

 Shallot, A, Ascalonicum. 

 Cive, A. Schcenoprasum. 



* Horse-radish and dandelion are perennials ; bnt as now grown they do not 

 occupy the ground more than a year. 



