THE CLASSIFICATION OF VEGETABLES 
199 
Group it. Condimental and Sweet Herbs. 
Dill, mint, sage, savory, tansy, thyme and many others. 
Group 12. Mushroom. 
Not discussed in this book. It is more generally regarded 
as a forcing crop. 
CLASS U. PERENNIAL VEGETABLES. 
Artichoke, globe (Cynara scolymus). 
Artichoke, Jerusalem (Helianthus tubcrosus). 
Asparagus (Asparagus officinalis). 
Rhubarb (Rheum rhaponticum). 
Sea kale (Crambe maritima). 
261. Requirements of the various groups. — Root crops 
(Group 1) thrive at comparatively low temperatures. 
They usually prefer sandy loams, and deep soils are also 
important for long-rooted crops. Sandy types of soil 
favor symmetrical development of roots and decrease the 
percentage of the small, fibrous roots objectionable in 
this class of vegetables. 
Tuber crops. (Group 2 .) The sweet potato requires 
a long season and high temperatures. Sandy soils are 
preferred. 
Bulb crops (Group 3) are hardy and may be grown 
successfully in many soil types, although sandy loams 
are best. They do not require high temperatures, but 
the soil must be well provided with humus and available 
plant food. 
Cole crops (Group 4) are hardy and require a cool sea- 
son, a fertile soil and an abundant supply of moisture. 
Potherb crops. The requirements of the “greens” 
(Group 5) are variable. (See Chapter XXI.) 
Salad crops (Group 6) are hardy. They require liberal 
feeding and an abundance of moisture. 
Pulse crops. (Group 7.) Soil and weather require- 
ments vary with each crop. 
Solanaceous crops (Group 8) are “tender” vegetables 
