The Hebrews had no names for cabbages, rapes, and turnips,[71] but there are Arab names: selgam for the Br. napus, and subjum or subjumi for Br. rapa; words which recur in Persian and even in Bengali, transferred perhaps from one species to another. The cultivation of these plants has therefore been diffused in the south-west of Asia since Hebrew antiquity.
Finally, every method, whether botanical, historical, or philological, leads us to the following conclusions:—
Firstly, the Brassicæ with fleshy roots were originally natives of temperate Europe.
Secondly, their cultivation was diffused in Europe before, and in Asia after, the Aryan invasion.
Thirdly, the primitive slender-rooted form of Brassica napus, called Br. campestris, had probably from the beginning a more extended range, from the Scandinavian peninsula towards Siberia and the Caucasus. Its cultivation was perhaps introduced into China and Japan, through Siberia, at an epoch which appears not to be much earlier than Greco-Roman civilization.
Fourthly, the cultivation of the various forms or species of Brassica was diffused throughout the south-west of Asia at an epoch later than that of the ancient Hebrews.
Skirret—Sium Sisarum, Linnæus.
This vivacious Umbellifer, furnished with several diverging roots in the form of a carrot, is believed to come from Eastern Asia. Linnæus indicates China, doubtfully; and Loureiro,[72] China and Cochin-China, where he says it is cultivated. Others have mentioned Japan and the Corea, but in these countries there are species which it is easy to confound with the one in question, particularly Sium Ninsi and Panax Ginseng. Maximowicz,[73] who has seen these plants in China and in Japan, and who has studied the herbariums of St. Petersburgh, recognizes only the Altaic region of Siberia and the North of Persia as the home of the wild Sium Sisarum. I am very doubtful whether it is to be found in the Himalayas or in China, since modern works on the region of the river Amoor and on British India make no mention of it.
It is doubtful whether the ancient Greeks and Romans knew this plant. The names Sisaron of Dioscorides, Siser of Columella and of Pliny,[74] are attributed to it. Certainly the modern Italian name sisaro or sisero seems to confirm this idea; but how could these authors have failed to notice that several roots descend from the base of the stem, whereas all the other umbels cultivated in Europe have but a single tap-root? It is just possible that the siser of Columella, a cultivated plant, may have been the parsnip; but what Pliny says of the siser does not apply to it. According to him it was a medicinal plant, inter medica dicendum.[75] He says that Tiberius caused a quantity to be brought every year from Germany, which proves, he adds, that it thrives in cold countries.