150 BKITISH PLANTS 



3. Storage of Food in Subterranean Organs (a) Tubers. 



(i.) Stem-tubers e.g., potato, Jerusalem artichoke, 

 (ii.) Root-tubers e.g., sweet potato. 

 (6) Rhizomes e.g., ginger, arrowroot. 



(c) Fleshy Roots. (i.) Of biennials e.g., carrot, tur- 

 nip, parsnip, swede, mangold, radish, beet. 



(ii.) Of perennials e.g., Manihot utilissima, the man- 

 dioc, from which tapioca is obtained. 



(d) Bulbs e.g., onion the leaves of which are full of 

 sugar. 



4. Edible Aerial Organs, yielding most of our table 

 vegetables. 



(a) Stems. (i.) Sugary pith e.g., sugar-cane. Maple- 

 sugar is obtained by boring holes in the stem of the sugar- 

 maple, a native of North America, when the sap is setting 

 towards the opening buds in spring. 



(ii.) Starchy pith e.g., the sago-palms from which 

 sago is obtained. 



(b) Leaves e.g., cabbage, lettuce, spinach. 



(c) Buds e.g., brussels - sprouts, from a variety of 

 cabbage. 



(d) Young Shoots e.g., asparagus. 



(e) Petioles e.g., celery, rhubarb. 



(/) Inflorescences e.g., cauliflower, broccoli, 



5. Seedlings (e.g., mustard and cress). 

 Fodder-Plants. Animals, in the main, eat the same 



vegetable food as man. Most of our domestic animals 

 are vegetable feeders, and in these the digestive organs 

 are adapted to the consumption of large quantities of 

 raw vegetation e.g., horse, cow, sheep, goat. Fodder- 

 plants for grazing animals include grasses, leguminous 

 herbs, and root-crops. 



Economic Botany is the study of plants from the point 

 of view of their utility to man. We have already dealt 

 with the most important side of the subject human food. 

 But plants have many other uses to man besides nutrition. 

 They offer to him material by means of which countless 

 needs are satisfied and many activities served. From 

 the vegetable world is drawn a large part of the raw 

 material which is used in the preparation of industrial 

 products cotton, flax, hemp, jute, oils, varnishes, rubber, 

 dyes, and timber. Vegetable products constitute a large 

 and often dominant source of wealth in every country. 



