130 Table Edible Plants The most prolific genera of food plants Genus Family Number of food species Total number of species % food species 10 11 12 Rosaceae Moraceae Dioscoreaceae Solanaceae Leguminosae Myrtaceae Ebenaceae Guttiferae Fagaceae Ericaceae Passifloraceae Cactaceae 205 137 110 100 80 79 69 68 67 66 58 52 2500–3000 700 600 1400–1700 800 800 200 400 470–1000 300–400 500 250 7–8 20 18 6–7 10 10 35 17 7–14 17–22 12 21 Ruibus Ficus Dioscorea Solarium Acacia Eugenia Diospyros Garcinia Quercus Vaccinium Passiflora Opuntia Table An estimate of food usage (as percentages of regional totals) from different sources World flora (Facciola, 1990) Leavesb Fruits Seeds Condiments, flavorings Tea, herbals Beverages Flowers, capers Rootsc Sapsd Barks Number of species Number of items (multiple uses) World flora (Kunkel, 1984)a Panama Isthmus United Kingdom (Duke, 1990) (Martin, 1976) Andes (NRC, 1989) Cambodia (Ito, 1969) Botswana (Campbell, 1986) 21.8 19.6 13.9 11.5 28.9 30.5 13.2 6.2 20.6 37.4 17.5 3.2 46.8 9.5 10.1 6.9 7.6 61.4 10.6 6.1 22.8 29.9 17.0 6.5 16.2 33.3 8.1 0.0 9.5 7.0 6.7 5.6 4.2 0.2 3000 2.9 0.8 4.0 8.7 3.9 0.9 1790 1.6 6.0 4.1 6.3 2.2 1.0 182 7.6 0.0 4.8 12.6 0.6 1.1 350 0.0 2.3 0.0 12.1 0.0 0.0 98 3.1 1.7 9.2 7.5 2.0 0.3 186 4.0 4.0 1.0 26.3 7.1 0.0 77 6311 2442 336 476 294 99 132 a A more detailed analysis of food usages appears in Table Including stems, sprouts, and meristems c Including bulbs and rhizomes d Including gums, latex, sugars, and masticatories b An analysis of the data compiled by Duke (1972) for Central America indicates that 85% of the plant species are used for a single purpose, 10% have two uses, 4% have three uses, and 1% have four uses (leaves, flowers, fruits, and seeds) A similar analysis of the 350 edible species of native British flora yields slightly different proportions: 78%, 19%, o3%, and o1% for one, two, three, and four purposes, respectively One of the exceptional cases of variability of uses is that of hops (Humulus lupulus) Its leaves, roots, flowers, and bark may be used as food and as condiment The pumpkin (Cucurbita moschata) provides fruits, seeds, flowers, young leaves, and shoots for human consumption It is clear from Table that some kinds of food are scarcely used, such as bark, flowers, sap, and liquorice In contrast, leaves (including stems, sprouts, seedlings, and shoots) and fruits seem to be the most preferred food Geographic Patterns of Food Plants On the basis of a sample of 1790 species from Kunkel’s list of food plants, it appears that edible herbs are more numerous than trees, shrubs, and vines Vines include all the climbing, creeping, and epiphytic plants Table shows that in decreasing order of species richness, the Indomalayan regions appear first, followed by the Neotropical, Palearctic, Ethiopian, Nearctic, and Australian (or Australasian) regions By means of a chi-square test, at a significance level Po.05, the Nearctic and Australian regions show greater, and the Palearctic lower, proportions of food trees than expected The proportion of edible shrubs does not vary significantly among regions, although at a Po.1 the Neotropics seem to have a higher proportion than the rest of the world The Palearctic region shows a higher and the Neotropics a lower proportion of herbs, whereas the latter region is richer in vines (Po.05) In contrast, the Northern Hemisphere (Palearctic and Nearctic regions) shows a significantly lower proportion of vines than the Southern Hemisphere According to biogeographic regions (Table 8), the Palearctic shows a significantly greater proportion of species that provide edible leaves, stems, and sprouts than the other regions The Australian region is characterized by a greater