PART II.
On the Study of Species, considered as to their Origin, their early Cultivation, and the Principal Facts of their Diffusion.[25]
CHAPTER I.
PLANTS CULTIVATED FOR THEIR SUBTERRANEAN PARTS, SUCH AS ROOTS, TUBERCLES, OR BULBS.[26]
Radish.—Raphanus sativus, Linnæus.
The radish is cultivated for what is called the root, which is, properly speaking, the lower part of the stem with the tap root.[27] Every one knows how the size, shape, and colour of those organs which become fleshy vary according to the soil or the variety.
There is no doubt that the species is indigenous in the temperate regions of the old world; but, as it has been cultivated in gardens from the earliest historic times, from China and Japan to Europe, and as it sows itself frequently round cultivated plots, it is difficult to fix upon its starting-point.
Formerly Raphanus sativus was confounded with kindred species of the Mediterranean region, to which certain Greek names were attributed; but Gay, the botanist, who has done a good deal towards eliminating these analogous forms,[28] considered R. sativus as a native of the East, perhaps of China. Linnæus also supposed this plant to be of Chinese origin, or at least that variety which is cultivated in China for the sake of extracting oil from the seeds.[29] Several floras of the south of Europe mention the species as subspontaneous or escaped from cultivation, never as spontaneous. Ledebour had seen a specimen found near Mount Ararat, had sown the seeds of it and verified the species.[30] However, Boissier,[31] in 1867, in his Eastern Flora, says that it is only subspontaneous in the cultivated parts of Anatolia, near Mersivan (according to Wied), in Palestine (on his own authority), in Armenia (according to Ledebour), and probably elsewhere, which agrees with the assertions found in European floras.[32] Buhse names a locality, the Ssahend mountains, to the south of the Caucasus, which appears to be far enough from cultivation. The recent Flora of British India[33] and the earlier Flora of Cochin-China by Loureiro, mention the radish only as a cultivated species. Maximowicz saw it in a garden in the north-east of China.[34] Thunberg speaks of it as a plant of general cultivation in Japan, and growing also by the side of the roads,[35] but the latter fact is not repeated by modern authors, who are probably better informed.[36]