Origin of Cultivated Plants

Herbaceous perennial plants are rare in categories A and D. They are only from two to four per cent., unless we include Brassica oleracea, and the variety of flax which is usually perennial (L. angustifolium), cultivated by the Swiss lake-dwellers. In nature herbaceous perennials constitute about forty per cent. of the Phanerogams.[2181 - The proportions which I give for the Phanerogams collectively are based upon an approximative calculation, made with the aid of the first two hundred pages of Steudel’s Nomenclator. They are justified by the comparison with several floras.]

A and D include twenty ligneous species out of forty-nine, that is about forty-one per cent. They are in the proportion of forty-three per cent. of the Phanerogams.

Thus the earliest husbandmen employed chiefly annuals or biennials, rather fewer woody species, and far fewer herbaceous perennials. These differences are due to the relative facility of cultivation, and the proportion of the evidently useful species in each division.

The species of the old world marked B have been in cultivation for more than two thousand years, but perhaps some of them belong to category A. The American species marked E were cultivated before the discoveries of Columbus, perhaps for more than two thousand years. Many other species marked (?) in the table date probably from an ancient epoch, but as they chiefly exist in countries without a literature and without archæological records we do not know their history. It is useless to insist upon such doubtful categories; on the other hand, the plants which we know to have been first cultivated in the old world less than two thousand years ago, and in America since its discovery, may be compared with plants of ancient cultivation.

These species of modern cultivation number sixty-one in the old world, marked C, and six in America, marked F; sixty-seven in all.

Classed according to their duration, they number thirty-seven per cent. annuals, seven to eight per cent. biennials, thirty-three per cent. herbaceous perennials, and twenty-two to twenty-three per cent. woody species.

The proportion of annuals or biennials is also here larger than in the whole number of plants, but it is not so large as among species of very ancient cultivation. The proportions of perennials and woody species are less than in the whole vegetable kingdom, but they are higher than among the species A, of very ancient cultivation.

The plants cultivated for less than two thousand years are chiefly artificial fodders, which the ancients scarcely knew; then bulbs, vegetables, medicinal plants (Cinchonas); plants with edible fruits, or nutritious seeds (buckwheats) or aromatic seeds (coffee).

Men have not discovered and cultivated within the last two thousand years a single species which can rival maize, rice, the sweet potato, the potato, the bread-fruit, the date, cereals, millets, sorghums, the banana, soy. These date from three, four, or five thousand years, perhaps even in some cases six thousand years. The species first cultivated during the Græco-Roman civilization and later nearly all answer to more varied or more refined needs. A great dispersion of the ancient species from one country to another took place, and at the same time a selection of the best varieties developed in each species. The introductions within the last two thousand years took place in a very irregular and intermittent manner. I cannot quote a single species cultivated for the first time after that date by the Chinese, the great cultivators of ancient times. The peoples of Southern and Western Asia innovated in a certain degree by cultivating the buckwheats, several cucurbitaceæ, a few alliums, etc. In Europe, the Romans and several peoples in the Middle Ages introduced the cultivation of a few vegetables and fruits, and that of several fodders. In Africa a few species were then first cultivated separately. After the voyages of Vasco di Gama and of Columbus a rapid diffusion took place of the species already cultivated in either hemisphere. These transports continued during three centuries without any introduction of new species into cultivation. In the two or three hundred years which preceded the discovery of America, and the two hundred which followed, the number of cultivated species remained almost stationary. The American strawberries, Diospyros virginiana, sea-kale, and Tetragonia expansa introduced in the eighteenth century, have but little importance. We must come to the middle of the present century to find new cultures of any value from the utilitarian point of view, such as Eucalyptus globulus of Australia and the Cinchonas of South America.

The mode of introduction of the latter species shows the great change which has taken place in the means of transport. Previously the cultivation of a plant began in the country where it existed, whereas the Australian Eucalyptus was first planted and sown in Algeria, and the Cinchonas of America in the south of Asia. Up to our own day botanical or private gardens had only diffused species already cultivated somewhere; now they introduce absolutely new cultures. The royal garden at Kew is distinguished in this respect, and other botanical gardens and acclimatization societies in England and elsewhere are making similar attempts. It is probable that tropical countries will greatly profit by this in the course of a century. Others will also find their advantage from the growing facility in the transport of commodities.

When a species has been once cultivated, it is rarely, perhaps never completely, abandoned. It continues to be here and there cultivated in backward countries, or those whose climate is especially favourable. I have passed over some of these species which are nearly abandoned, such as dyer’s woad (Isatis tinctoria), mallow (Malva sylvestris), a vegetable used by the Romans, and certain medicinal plants formerly much used, such as fennel, cummin, etc., but it is certain that they are still grown in some places.

The competition of species causes the cultivation of some to diminish, of others to increase; besides, vegetable dyes and medicinal plants are rivalled by the discoveries of chemists. Woad, madder, indigo, mint, and several simples must give way before the invasion of chemical products. It is possible that men may succeed in making oil, sugar, and flour, as honey, butter, and jellies are already made, without employing organic substances. Nothing, for instance, would more completely change agricultural conditions than the manufacture of flour from its known inorganic elements. In the actual state of science, there are still products which will be more and more required of the vegetable kingdom; these are textile substances, tan, indiarubber, gutta-percha, and certain spices. As the forests where these are found are gradually destroyed, and these substances are at the same time more in demand, there will be the greater inducement to cultivate certain species.

These usually belong to tropical countries. It is in these regions also, particularly in South America, that fruit trees will be more cultivated – those of the order Anonaceæ for instance, of which the natives and botanists already recognize the value. Probably the number of plants suitable for fodder, and of forest trees which can live in hot dry countries, will be increased. The additions will not be numerous in temperate climates, nor especially in cold regions.

From these data and reflections it is probable that at the end of the nineteenth century men will cultivate on a large scale and for use about three hundred species. This is a small proportion of the one hundred and twenty or one hundred and forty thousand in the vegetable kingdom; but in the animal world the proportion of creatures subject to the will of man is far smaller. There are not perhaps more than two hundred species of domestic animals – that is, reared for our use, – and the animal kingdom reckons millions of species. In the great class of molluscs the oyster alone is cultivated, and in that of the Articulata, which counts ten times more species than the vegetable kingdom, we can only name the bee and two or three silk-producing insects. Doubtless the number of species of animals and vegetables which may be reared or cultivated for pleasure or curiosity is very large: witness menageries and zoological and botanical gardens, but I am only speaking here of useful plants and animals, in general and customary employment.

Article III.—Cultivated Plants known or not known in a Wild State

Science has succeeded in discovering the geographical origin of nearly all cultivated species; but there is less progress in the knowledge of species in a natural state – that is wild, far from cultivation and dwellings. There are species which have not been discovered in this condition, and others whose specific identity and truly wild condition are doubtful.

In the following enumeration I have classed the species according to the degree of certainty as to the wild character, and the nature of the doubts where such exist.[2182 - The species in italics are of very ancient cultivation (A or D), those marked with an asterisk have been less than two thousand years in cultivation (C or F).]

1. Spontaneous species, that is wild, seen by several botanists far from dwellings and cultivation, with every appearance of indigenous plants, and under a form identical with one of the cultivated varieties. These are the species which are not enumerated below; they are 169 in number.

Among these 169 species, 31 belong to the categories A and D, of very ancient cultivation, 56 have been in cultivation less than two thousand years, C, and the others are of modern or unknown date.

2. Seen and gathered in the same conditions, but by a single botanist in a single locality. Three species.

Cucurbita maxima, Faba vulgaris, Nicotiana Tabacum.

3. Seen and mentioned but not gathered in the same conditions by one or two authors and botanists, more or less ancient, who may have been mistaken. Two species.

Carthamus tinctorius, Triticum vulgare.

4. Gathered wild by botanists in several localities under a form slightly different to those which are cultivated, but which most authors have no hesitation in classing with the species. Four species.

Olea europæa, Oryza sativa, Solanum tuberosum, Vitis vinifera.

5. Wild, gathered by botanists in several localities under forms considered by some botanists as constituting different species, while others treat them as varieties. Fifteen species.

Allium ampeloprasum porrum, Cichorium Endivia, var., Crocus sativus, var., *Cucumis melo, Cucurbita Pepo, Helianthus tuberosus, Latuca scariola sativa, Linum usitatissimum annuum, Lycopersicum esculentium, Papaver somniferum, Pyrus nivalis var., *Ribes grossularia, Solanum Melongena, *Spinacia oleracea var., Triticum monococcum.

6. Subspontaneous, that is half-wild, similar to one or other of the cultivated forms, but possibly plants escaped from cultivation, judging from the locality. Twenty-four species.

Agava americana, Amarantus gangeticus, Amygdalus persica, Areca catechu, *Avena orientalis, Avena sativa, *Cajanus indicus, Cicer arietinum, Citrus decumana, Cucurbita moschata, Dioscorea japonica, Ervum Ervilia, Ervum lens, Fagopyrum emarginatum, Gossypium barbadense, Holcus saccharatus, Holcus sorghum, Indigofera tinctoria, Lepidum sativum, Maranta arundinacea, Nicotiana rustica, Panicum miliaceum, Raphanus sativus, Spergula arvensis.

7. Subspontaneous like the preceding, but different enough from the cultivated varieties to lead the majority of authors to regard them as distinct species. Three species.

*Allium ascalonicum (variety of A. cepa?), Allium scorodoprasum (variety of A. sativum?), Secale cereale (variety of one of the perennial species of Secale?).

8. Not discovered in a wild state nor even half-wild, derived perhaps from cultivated species at the beginning of agriculture, but too different not to be commonly regarded as distinct species. Three species.

Hordeum hexastichon (derived from H. distichon?), Hordeum vulgare (derived from H. distichon?), Triticum spelta (derived from T. vulgare?)

9. Not discovered in a wild state nor even half-wild, but originating in countries which are not completely explored, and belonging perhaps to little-known wild species of these countries. Six species.

Arachis hypogea, Carophyllus aromaticus, Convolvulus batatas, *Dolichos lubia, Manihot utilissima, Phaseolus vulgaris.

10. Not found in a wild state, nor even half-wild, but originating in countries which are not sufficiently explored, or in similar countries which cannot be defined, more different than the latter from known wild species. Eighteen species.

Amorphophallus konjak, Arracacha esculenta, Brassica chinensis, Capsicum annuum, Chenopodium quinoa,[2183 - Since this list was printed, I have been informed that the quinoa is wild in Chili. Some of the figures need modification in consequence of this error.] Citrus nobilis, Cucurbita ficifolia, Dioscorea alata, Dioscorea Batatas, Dioscorea sativa, Eleusine coracana, Lucuma mammosa, Nephelium Litchi, *Pisum sativum, Saccharum officinarum, Sechium edule, *Tricosanthes anguina, Zea mays.

Total 247 species.

These figures show that there are 193 species known to be wild, 27 doubtful, as half-wild, and 27 not found wild.

I believe that these last will be found some time or other, if not under one of the cultivated forms, at least in an allied form called species or variety according to the author. To attain this result tropical countries will have to be more thoroughly explored, collectors must be more attentive to localities, and more floras must be published of countries now little known, and good monographs of certain genera based upon the characters which vary least in cultivation.

A few species having their origin in countries fairly well explored, and which it is impossible to confound with others because each is unique in its genus, have not been found wild, or only once, which leads us to suppose that they are extinct in nature, or rapidly becoming so. I allude to maize and the bean (see pp. 387 and 316). I mention also in Article IV. other plants which appear to be becoming extinct in the last few thousand years. These last belong to genera which contain many species, which renders the hypothesis less probable;[2184 - For reasons which I cannot here express, monotypical genera are for the most part in process of extinction.] but, on the other hand, they are rarely seen at a distance from cultivated ground, and they hardly ever become naturalized, that is wild, which shows a certain feebleness or a tendency to become the prey of animals and parasites.

The 67 species cultivated for less than two thousand years (C, F) are all found wild, except the species marked with an asterisk, which have not been found or which are subject to doubts. This is a proportion of eighty-three per cent.

What is more remarkable is that the great majority of species cultivated for more than four thousand years (A), or in America for three thousand or four thousand years (D), still exist wild in a form identical with some one of the cultivated varieties. Their number is thirty-one out of forty-nine, or sixty-three per cent. In categories 9 and 10 there are only two of these species of very ancient cultivation, or four per cent., and these are two species which probably exist no longer as wild plants.

I believed, à priori, that a great number of the species cultivated for more than four thousand years would have altered from their original condition to such a degree that they could no longer be recognized among wild plants. It appears, on the contrary, that the forms anterior to cultivation have commonly remained side by side with those which cultivators employed and propagated from century to century. This may be explained in two ways: 1. The period of four thousand years is short compared to the duration of most of the specific forms in phanerogamous plants. 2. The cultivated species receive, outside of cultivated ground, continual reinforcements from the seeds which man, birds, and different natural agents disperse and transport in a thousand ways. Naturalizations produced in this manner often confound the wild plants with the cultivated ones, and the more easily that they fertilize each other since they belong to the same species. This fact is clearly demonstrated in the case of a plant of the old world cultivated in America, in gardens, and which, later, becomes naturalized on a large scale in the open country or the woods, like the cardoon at Buenos Ayres, and the oranges in several American countries. Cultivation widens areas, and supplements the deficits which the natural reproduction of the species may present. There are, however, a few exceptions, which are worth mentioning in a separate article.

Article IV.—Cultivated Plants which are Extinct, or becoming Extinct in a Wild State

These species to which I allude present three remarkable characters: —

1. They have not been found wild, or only once or twice, and often doubtfully, although the regions whence they come have been visited by several botanists.

2. They have not the faculty of sowing themselves, and propagating indefinitely outside cultivated ground. In other terms, in such cases they do not pass out of the condition of adventitious plants.

3. It cannot be supposed that they are derived within historic times from certain allied species.

These three characters are found united in the following species: – Bean (Faba vulgaris), chick-pea (Cicer arietinum), ervilla (Ervum Ervilia), lentil (Ervum lens), tobacco (Nicotiana tabacum), wheat (Triticum vulgare), maize (Zea mays). The sweet potato (Convolvulus batatas) should be added if the kindred species were better known to be distinct, and the carthamine (Carthamus tinctorius) if the interior of Arabia had been explored, and we had not found a mention of the plant in an Arabian author.