Origin of Cultivated Plants

The climate of the coast of Chili is continued upon the heights as we follow the chain of the Andes, and the cultivation of the potato is of ancient date in the temperate regions of Peru, but the wild character of the species there is not so entirely proved as in the case of Chili.127 Pavon declared he found it on the coast at Chancay, and near Lima. The heat of these districts seems very great for a species which requires a temperate or even a rather cold climate. Moreover, the specimen in Boissier’s herbarium, gathered by Pavon, belongs, according to Dunal,128 to another species, to which he has given the name of S. immite. I have seen the authentic specimen, and have no doubt that it belongs to a species distinct from the S. tuberosum. Sir W. Hooker129 speaks of McLean’s specimen, gathered in the hills round Lima, without any information as to whether it was found wild. The specimens (more or less wild) which Matthews sent from Peru to Sir W. Hooker belong, according to Sir Joseph,130 to varieties which differ a little from the true potato. Mr. Hemsley,131 who has seen them recently in the herbarium at Kew, believes them to be “distinct forms, not more distinct, however, than certain varieties of the species.”

Weddell,132 whose caution in this matter we already know, expresses himself as follows: – “I have never found Solanum tuberosum in Peru under such circumstances as left no doubt that it was indigenous; and I even declare that I do not attach more belief to the wild nature of other plants found scattered on the Andes outside Chili, hitherto considered as indigenous.”

On the other hand. M. Ed. André133 collected with great care, in two elevated and wild districts of Columbia, and in another near Lima, specimens which he believed he might attribute to S. tuberosum. M. André has been kind enough to lend them to me. I have compared them attentively with the types of Dunal’s species in my herbarium and in that of M. Boissier. None of these Solanaceæ belong, in my opinion, to S. tuberosum, although that of La Union, near the river Cauca, comes nearer than the rest. None – and this is yet more certain – answers to S. immite of Dunal. They are nearer to S. columbianum of the same author than to S. tuberosum or S. immite. The specimen from Mount Quindio presents a singular characteristic – it has pointed ovoid berries.134

In Mexico the tuberous Solanums attributed to S. tuberosum, or, according to Hemsley,135 to allied forms, do not appear to be identical with the cultivated plant. They belong to S. Fendleri, which Dr. Asa Gray considered at first as a separate species, and afterwards136 as a variety of S. tuberosum or of S. verrucosum.

We may sum up as follows: —

1. The potato is wild in Chili, in a form which is still seen in our cultivated plants.

2. It is very doubtful whether its natural home extends to Peru and New Granada.

3. Its cultivation was diffused before the discovery of America from Chili to New Granada.

4. It was introduced, probably in the latter half of the sixteenth century, into that part of the United States now known as Virginia and North Carolina.

5. It was imported into Europe between 1580 and 1585, first by the Spaniards, and afterwards by the English, at the time of Raleigh’s voyages to Virginia.137

Batata, or Sweet Potato—Convolvulus batatas, Linnæus; Batatas edulis, Choisy.

The roots of this plant, swelled into tubers, resemble potatoes, whence it arose that sixteenth-century navigators applied the same name to these two very different species. The sweet potato belongs to the Convolvulus family, the potato to the Solanum family; the fleshy parts of the former are roots, those of the latter subterranean branches.138 The sweet potato is sugary as well as farinaceous. It is cultivated in all countries within or near the tropics, and perhaps more in the new than in the old world.139

Its origin is, according to a great number of authors, doubtful. Humboldt,140 Meyen,141 and Boissier142 hold to its American, Boyer,143 Choisy,144 etc., to its Asiatic origin. The same diversity is observed in earlier works. The question is the more difficult since the Convolvulaceæ is one of the most widely diffused families, either from a very early epoch or in consequence of modern transportation.

There are powerful arguments in favour of an American origin. The fifteen known species of the genus Batatas are all found in America; eleven in that continent alone, four both in America and the old world, with possibility or probability of transportation. The cultivation of the common sweet potato is widely diffused in America. It dates from a very early epoch. Marcgraff145 mentions it in Brazil under the name of jetica. Humboldt says that the name camote comes from a Mexican word. The word Batatas (whence comes by a mistaken transfer the word potato) is given as American. Sloane and Hughes146 speak of the sweet potato as of a plant much cultivated, and having several varieties in the West Indies. They do not appear to suspect that it had a foreign origin. Clusius, who was one of the first to mention the sweet potato, says he had eaten some in the south of Spain, where it was supposed to have come from the new world.147 He quotes the names Batatas, camotes, amotes, ajes,148 which were foreign to the languages of the old world. The date of his book is 1601. Humboldt149 says that, according to Gomara, Christopher Columbus, when he appeared for the first time before Queen Isabella, offered her various productions from the new world, sweet potatoes among others. Thus, he adds, the cultivation of this plant was already common in Spain from the beginning of the sixteenth century. Oviedo,150 writing in 1526, had seen the sweet potato freely cultivated by the natives of St. Domingo, and had introduced it himself at Avila, in Spain. Rumphius151 says positively that, according to the general opinion, sweet potatoes were brought by the Spanish Americans to Manilla and the Moluccas, whence the Portuguese diffused it throughout the Malay Archipelago. He quotes the popular names, which are not Malay, and which indicate an introduction by the Castillians. Lastly, it is certain that the sweet potato was unknown to the Greeks, Romans, and Arabs; that it was not cultivated in Egypt even eighty years ago,152 a fact which it would be hard to explain if we supposed its origin to be in the old world.

On the other hand, there are arguments in favour of an Asiatic origin. The Chinese Encyclopædia of Agriculture speaks of the sweet potato, and mentions different varieties;153 but Bretschneider154 has proved that the species is described for the first time in a book of the second or third century of our era. According to Thunberg,155 the sweet potato was brought to Japan by the Portuguese. Lastly, the plant cultivated at Tahiti, in the neighbouring islands, and in New Zealand, under the names umara, gumarra, and gumalla, described by Forster156 under the name of Convolvulus chrysorhizus, is, according to Sir Joseph Hooker, the sweet potato.157 Seemann158 remarks that these names resemble the Quichuen name of the sweet potato in America, which is, he says, cumar. The cultivation of the sweet potato became general in Hindustan in the eighteenth century.159 Several popular names are attributed to it, and even, according to Piddington,160 a Sanskrit name, ruktalu, which has no analogy with any name known to me, and is not in Wilson’s Sanskrit Dictionary. According to a note given me by Adolphe Pictet, ruktalu seems a Bengalee name composed from the Sanskrit alu (Rukta plus âlu, the name of Arum campanulatum). This name in modern dialects designates the yam and the potato. However, Wallich161 gives several names omitted by Piddington. Roxburgh162 mentions no Sanskrit name. Rheede163 says the plant was cultivated in Malabar, and mentions common Indian names.

The arguments in favour of an American origin seem to me much stronger. If the sweet potato had been known in Hindustan at the epoch of the Sanskrit language it would have become diffused in the old world, since its propagation is easy and its utility evident. It seems, on the contrary, that this cultivation remained long unknown in the Sunda Isles, Egypt, etc. Perhaps an attentive examination might lead us to share the opinion of Meyer,164 who distinguished the Asiatic plant from the American species. However, this author has not been generally followed, and I suspect that if there is a different Asiatic species it is not, as Meyer believed, the sweet potato described by Rumphius, which the latter says was brought from America, but the Indian plant of Roxburgh.

Sweet potatoes are grown in Africa; but either the cultivation is rare, or the species are different. Robert Brown165 says that the traveller Lockhardt had not seen the sweet potato of whose cultivation the Portuguese missionaries make mention. Thonning166 does not name it. Vogel brought back a species cultivated on the western coast, which is certainly, according to the authors of the Flora Nigritiana, Batatas paniculata of Choisy. It was, therefore, a plant cultivated for ornament or for medicinal purposes, for its root is purgative.167 It might be supposed that in certain countries in the old or new world Ipomœa tuberosa. L., had been confounded with the sweet potato; but Sloane168 tells us that its enormous roots are not eatable.169

Ipomœa mammosa, Choisy (Convolvulus mammosus, Loureiro; Batata mammosa, Rumphius), is a Convolvulaceous plant with an edible root, which may well be confounded with the sweet potato, but whose botanical character is nevertheless distinct. This species grows wild near Amboyna (Rumphius), where it is also cultivated. It is prized in Cochin-China.

As for the sweet potato (Batatas edulis), no botanist, as far as I know, has asserted that he found it wild himself, either in India or America.170 Clusius171 affirms upon hearsay that it grows wild in the new world and in the neighbouring islands.

In spite of the probability of an American origin, there remains, as we have seen, much that is unknown or uncertain touching the original home and the transport of this species, which is a valuable one in hot countries. Whether it was a native of the new or of the old world, it is difficult to explain its transportation from America to China at the beginning of our era, and to the South Sea Islands at an early epoch, or from Asia and from Australia to America at a time sufficiently remote for its cultivation to have been early diffused from the Southern States to Brazil and Chili. We must assume a prehistoric communication between Asia and America, or adopt another hypothesis, which is not inapplicable to the present case. The order Convolvulaceæ is one of those rare families of dicotyledons in which certain species have a widely extended area, extending even to distant continents.172 A species which can at the present day endure the different climates of Virginia and Japan may well have existed further north before the epoch of the great extension of glaciers in our hemisphere, and prehistoric men may have transported it southward when the climatic conditions altered. According to this hypothesis, cultivation alone preserved the species, unless it is at last discovered in some spot in its ancient habitation – in Mexico or Columbia, for instance.173

Beetroot—Beta vulgaris and B. maritima, Linnæus; Beta vulgaris, Moquin.

This plant is cultivated sometimes for its fleshy root (red beet), sometimes for its leaves, which are used as a vegetable (white beet), but botanists are generally agreed in not dividing the species. It is known from other examples that plants slender rooted by nature easily become fleshy rooted from the effects of soil or cultivation.

The slender-rooted variety grows wild in sandy soil, and especially near the sea in the Canary Isles, and all along the coasts of the Mediterranean Sea, and as far as the Caspian Sea, Persia, and Babylon,174 perhaps even as far as the west of India, whence a specimen was brought by Jaquemont, although it is not certain that it was growing wild. Roxburgh’s Indian flora, and Aitchison’s more recent flora of the Punjab and of the Sindh, only mention the plant as a cultivated species.

It has no Sanskrit name,175 whence it may be inferred that the Aryans had not brought it from western temperate Asia, where it exists. The nations of Aryan race who had previously migrated into Europe probably did not cultivate it, for I find no name common to the Indo-European languages. The ancient Greeks, who used the leaves and roots, called the species teutlion;176 the Romans, beta. Heldreich177 gives also the ancient Greek name sevkle, or sfekelie which resembles the Arab name selg, silq,178 among the Nabatheans. The Arab name has passed into the Portuguese selga. No Hebrew name is known. Everything shows that its cultivation does not date from more than three or four centuries before the Christian era.

The red and white roots were known to the ancients, but the number of varieties has greatly increased in modern times, especially since the beetroot has been cultivated on a large scale for the food of cattle and for the production of sugar. It is one of the plants most easily improved by selection, as the experiments of Vilmorin have proved.179

Manioc—Manihot utilissima, Pohl; Jatropha manihot, Linnæus.

The manioc is a shrub belonging to the Euphorbia family, of which several roots swell in their first year; they take the form of an irregular ellipse, and contain a fecula (tapioca) with a more or less poisonous juice.

It is commonly cultivated in the equatorial or tropical regions, especially in America from Brazil to the West Indies. In Africa the cultivation is less general, and seems to be more recent. In certain Asiatic colonies it is decidedly of modern introduction. It is propagated by budding.

Botanists are divided in opinion whether the innumerable varieties of manioc should be regarded as forming one, two, or several different species. Pohl180 admitted several besides his Manihot utilissima, and Dr. Müller,181 in his monograph on the Euphorbiaceæ, places the variety aipi in an allied species, M. palmata, a plant cultivated with the others in Brazil, and of which the root is not poisonous. This last character is not so distinct as might be believed from certain books and even from the assertions of the natives. Dr. Sagot,182 who has compared a dozen varieties of manioc cultivated at Cayenne, says expressly, “There are maniocs more poisonous than others, but I doubt whether any are entirely free from noxious principles.”

It is possible to account for these singular differences of properties in very similar plants by the example of the potato. The Manihot and Solanum tuberosum both belong to suspected families (Euphorbiaceæ and Solanaceæ). Several of their species are poisonous in some of their organs; but the fecula, wherever it is found, is never harmful, and the same holds good of the cellular tissue, freed from all deposit; that is to say, reduced to cellulose. In the preparation of cassava, or manioc flour, great care is taken to scrape the outer skin of the root, then to pound or crush the fleshy part so as to express the more or less poisonous juice, and finally the paste is submitted to a baking which expels the volatile parts.183 Tapioca is the pure fecula without the mixture of the tissues which still exist in the cassava. In the potato the outer pellicle contracts noxious qualities when it is allowed to become green by exposure to the light, and it is well known that unripe or diseased tubers, containing too small a proportion of fecula with much sap, are not good to eat, and would cause positive harm to persons who consumed any quantity of them. All potatoes, and probably all maniocs, contain something harmful, which is observed even in the products of distillation, and which varies with several causes; but only matter foreign to the fecula should be mistrusted.

The doubts about the number of species into which the cultivated manihots should be divided are no source of difficulty regarding the question of geographic origin. On the contrary, we shall see that they are an important means of proving an American origin.

The Abbé Raynal had formerly spread the erroneous opinion that the manioc was imported into America from Africa. Robert Brown184 denied this in 1818, but without giving reasons in support of his opinion; and Humboldt,185 Moreau de Jonnes,186 and Saint Hilaire187 insisted upon its American origin. It can hardly be doubted for the following reasons: —

1. Maniocs were cultivated by the natives of Brazil, Guiana, and the warm region of Mexico before the arrival of the Europeans, as all early travellers testify. In the West Indies this cultivation was, according to Acosta,188 common enough in the sixteenth century to inspire the belief that it was also there of a certain antiquity.

2. It is less widely diffused in Africa, especially in regions at a distance from the west coast. It is known that manioc was introduced into the Isle of Bourbon by the Governour Labourdonnais.189 In Asiatic countries, where a plant so easy to cultivate would probably have spread had it been long known on the African continent, it is mentioned here and there as an object of curiosity of foreign origin.190

3. The natives of America had several ancient names for the varieties of manioc, especially in Brazil,191 which does not appear to have been the case in Africa, even on the coast of Guinea.192

4. The varieties cultivated in Brazil, in Guiana, and in the West Indies are very numerous, whence we may presume a very ancient cultivation. This is not the case in Africa.

5. The forty-two known species of the genus Manihot, without counting M. utilissima, are all wild in America; most of them in Brazil, some in Guiana, Peru, and Mexico; not one in the old world.193 It is very unlikely that a single species, and that the cultivated one, was a native both of the old and of the new world, and all the more so since in the family Euphorbiaceæ the area of the woody species is usually restricted, and since phanerogamous plants are very rarely common to Africa and America.

The American origin of the manioc being thus established, it may be asked how the species has been introduced into Guinea and Congo. It was probably the result of the frequent communications established in the sixteenth century by Portuguese merchants and slave-traders.

The Manihot utilissima and the allied species or variety called aipi, which is also cultivated, have not been found in an undoubtedly wild state. Humboldt and Bonpland, indeed, found upon the banks of the Magdalena a plant of Manihot utilissima which they called almost wild,194 but Dr. Sagot assures me that it has not been found in Guiana, and that botanists who have explored the hot region in Brazil have not been more fortunate. We gather as much from the expressions of Pohl, who has carefully studied these plants, and who was acquainted with the collections of Martius, and had no doubt of their American origin. If he had observed a wild variety identical with those which are cultivated, he would not have suggested the hypothesis that the manioc is obtained from his Manihot pusilla195 of the province of Goyaz, a plant of small size, and considered as a true species or as a variety of Manihot palmata.196 Martius declared in 1867, that is after having received a quantity of information of a later date than his journey, that the plant was not known in a wild state.197 An early traveller, usually accurate, Piso,198 speaks of a wild mandihoca, of which the Tapuyeris, the natives of the coast to the north of Rio Janeiro, ate the roots. “It is,” he says, “very like the cultivated plant;” but the illustration he gives of it appears unsatisfactory to authors who have studied the maniocs. Pohl attributes it to his M. aipi, and Dr. Müller passes it over in silence. For my part, I am disposed to believe what Piso says, and his figure does not seem to me entirely unsatisfactory. It is better than that by Vellozo, of a wild manioc which is doubtfully attributed to M. aipi.199 If we do not accept the origin in eastern tropical Brazil, we must have recourse to two hypotheses: either the cultivated maniocs are obtained from one of the wild species modified by cultivation, or they are varieties which exist only by the agency of man after the disappearance of their fellows from modern wild vegetation.

Garlic—Allium sativum, Linnæus.

Linnæus, in his Species Plantarum, indicates Sicily as the home of the common garlic; but in his Hortus Cliffortianus, where he is usually more accurate, he does not give its origin. The fact is that, according to all the most recent and complete floras of Sicily, Italy, Greece, France, Spain, and Algeria, garlic is not considered to be indigenous, although specimens have been gathered here and there which had more or less the appearance of being so. A plant so constantly cultivated and so easily propagated may spread from gardens and persist for a considerable time without being wild by nature. I do not know on what authority Kunth200 mentions that the species is found in Egypt. According to authors who are more accurate201 in their accounts of the plants of that country, it is only found there under cultivation. Boissier, whose herbarium is so rich in Eastern plants, possesses no wild specimens of it. The only country where garlic has been found in a wild state, with the certainty of its really being so, is the desert of the Kirghis of Sungari; bulbs were brought thence and cultivated at Dorpat,202 and specimens were afterwards seen by Regel.203 The latter author also says that he saw a specimen which Wallich had gathered as wild in British India; but Baker,204 who had access to the rich herbarium at Kew, does not speak of it in his review of the “Alliums of India, China, and Japan.”

Let us see whether historical and philological records confirm the fact of an origin in the south-west of Siberia alone.

Garlic has been long cultivated in China under the name of suan. It is written in Chinese by a single sign, which usually indicates a long known and even a wild species.205 The floras of Japan206 do not mention it, whence I gather that the species was not wild in Eastern Siberia and Dahuria, but that the Mongols brought it into China.

According to Herodotus, the ancient Egyptians made great use of it. Archæologists have not found the proof of this in the monuments, but this may be because the plant was considered unclean by the priests.207

There is a Sanskrit name, mahoushouda,208 become loshoun in Bengali, and to which appears to be related the Hebrew name schoum or schumin,209 which has produced the Arab thoum or toum. The Basque name baratchouria is thought by de Charencey210 to be allied with Aryan names. In support of his hypothesis I may add that the Berber name, tiskert, is quite different, and that consequently the Iberians seem to have received the plant and its name rather from the Aryans than from their probable ancestors of Northern Africa. The Lettons call it kiplohks, the Esthonians krunslauk, whence probably the German Knoblauch. The ancient Greek name appears to have been scorodon, in modern Greek scordon. The names given by the Slavs of Illyria are bili and cesan. The Bretons say quinen,211 the Welsh craf, cenhinnen, or garlleg, whence the English garlic. The Latin allium has passed into the languages of Latin origin.212 This great diversity of names intimates a long acquaintance with the plant, and even an ancient cultivation in Western Asia and in Europe. On the other hand, if the species has existed only in the land of the Kirghis, where it is now found, the Aryans might have cultivated it and carried it into India and Europe; but this does not explain the existence of so many Keltic, Slav, Greek, and Latin names which differ from the Sanskrit. To explain this diversity, we must suppose that its original abode extended farther to the west than that known at the present day, an extension anterior to the migrations of the Aryans.