EDIBLE PRODUCTS 
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skia, Peumus, Sechium, Spondias, Tamarindus, Vaccinium, 
Vitellaria, Zanthoxylum, Zizyphus, &c. 
Underground reserve stores are also an important source 
of food. The chief are perhaps the tubers of potato (So- 
lanum) and yam (Dioscorea), the rhizomes of arrowroot 
(Maranta) and taro (Colocasia), the roots of cassava or 
tapioca (Manihot), sweet potato (Ipomoea), turnip (Brassica), 
beetroot (Beta), &c., the bulbs of onion, garlic, &c. (Allium), 
and many more. To these may be added the genera Arum, 
Alocasia, Canna, Commelina, Daucus, Helianthus, Oxalis, 
Pachyrrhizus, Peucedanum, Plectranthus, Priva, Raphanus, 
Scilla, Scorzonera, Selinum, Stachys, Tragopogon, Tropae- 
olum, Ullucus, Xanthosoma, and others. There are many 
plants with small tubers or other underground parts that 
might be improved by cultivation and selection. 
Reserves are commonly stored in stems, in trees and 
shrubs. Starchy food products are obtained from the pith 
of the stems of sago (Metroxylon) and other palms, Cycas, 
Alsophila, &c., and sugar from Saccharum, Acer, &c., and 
from many palms in which the upward current of sap from 
the reserve stores is tapped for this purpose. 
Reserves used' as food occur in leaves in cabbages, &c. 
(Brassica) and in the inflorescences in cauliflower (Brassica). 
The leaves of many other plants are eaten, but are of no 
very high food value, e.g. celery (Apium), sea-kale (Crambe), 
lettuce (Lactuca), cress (Lepidium), rhubarb (Rheum), 
spinach (Spinacia), Ceratopteris, Chenopodium, Eremurus, 
Foeniculum, Myrrhis, Scorzonera, Tetragonia, &c. The 
young bud of Oreodoxa and other palms is eaten as cabbage ; 
the young flower heads of the artichoke (Cynara), and the 
young shoots of Asparagus and some bamboos are also use- 
ful vegetables. 
Several of these products are rather co?idiments or spices 
than food. To them may be added many more, e.g. mustard 
(seeds of Brassica), capers (buds of Capparis), cayenne 
pepper and chillies (Capsicum), caraway (Carum), cinnamon 
(bark of Cinnamomum), horse-radish (Cochlearia), cloves 
(buds of Eugenia), cress (Lepidium), nutmeg and mace 
(Myristica), watercress (Nasturtium), dill (Peucedanum), 
anise (Pimpinella), pepper (Piper), vanilla (Vanilla), ginger 
