[40] Webb, Phytogr. Canar., p. 83; Iter. Hisp., p. 71; Bentham, Fl. Hong Kong, p. 17; Hooker, Fl. Brit. Ind., i. p. 166.

[41] Willkomm and Lange, Prod. Fl. Hisp., iii. p. 748; Viviani, Flor. Dalmat., iii. p. 104; Boissier, Fl. Orient., i. p. 401.

[42] Webb, Phytographia Canariensis, i. p. 83.

[43] Webb, Iter. Hispaniense, 1838, p. 72.

[44] Carrière, Origine des Plantes Domestiques démontrée par la Culture du Radis Sauvage, in 8vo, 24 pp., 1869.

[45] Ledebour, Fl. Ross.; Boissier, Fl. Orient. Works on the flora of the valley of the Amur.

[46] A. de Candolle, Géographie Botanique Raisonnée, p. 654.

[47] Delalande, Hœdic et Houat, 8vo pamphlet, Nantes, 1850, p. 109.

[48] Hardouin, Renou, and Leclerc, Catalogue du Calvados, p. 85; De Brebisson, Fl. de Normandie, p. 25.

[49] Watson, Cybele, i. p. 159.

[50] Babington, Manual of Brit. Bot., 2nd edit., p. 28.

[51] Ledebour, Fl. Ross., i. p. 159.

[52] Grisebach, Spicilegium Fl. Rumel., i. p. 265.

[53] Fries, Summa, p. 30.

[54] Miquel, Disquisitio pl. regn. Batav.

[55] Moritzi, Dict. Inéd. des Noms Vulgaires.

[56] Moritzi, ibid.; Viviani, Fl. Dalmat., iii. p. 322.

[57] Neilreich, Fl. Wien, p. 502.

[58] Linnæus, Fl. Suecica, No. 540.

[59] H. Davies, Welsh Botanology, p. 63.

[60] In turnips and swedes the swelled part is, as in the radish, the lower part of the stem, below the cotyledons, with a more or less persistent part of the root. (See Turpin. Ann. Sc. Natur., ser. 1, vol. xxi.) In the Kohl-rabi (Brassica oleracea caulo-rapa) it is the stem.

[61] This classification has been the subject of a paper by Augustin Pyramus de Candolle, Transactions of the Horticultural Society, vol. v.

[62] Fries, Summa Veget. Scand., i. p. 29.

[63] Ledebour, Fl. Ross., i. p. 216.

[64] Boissier, Flora Orientalis; Sir J. Hooker, Flora of British India; Thunberg, Flora Japonica; Franchet and Savatier, Enumeratio Plantarum Japonicarum.

[65] Piddington, Index.

[66] Kæmpfer, Amœn., p. 822.

[67] Davies, Welsh Botanology, p. 65.

[68] Moritzi, Dict. MS., compiled from published floras.

[69] Threlkeld, Synopsis Stirpium Hibernicarum, 1 vol. in 8vo, 1727.

[70] Moritzi, Dict. MS.

[71] Rosenmüller, Biblische Naturgeschichte, vol. i., gives none.

[72] Linnæus, Species, p. 361; Loureiro, Fl. Cochinchinensis, p. 225.

[73] Maximowicz, Diagnoses Plantarum Japonicæ et Manshuriæ, in Mélanges Biologiques du Bulletin de l’Acad., St. Petersburg, decad 13, p. 18.

[74] Dioscorides, Mat. Med., 1. 2, c. 139; Columella, 1. 11, c. 3, 18, 35; Lenz, Bot. der Alten, p. 560.

[75] Pliny, Hist. Plant., 1. 19, c. 5.

[76] Nemnich, Polygl. Lexicon, ii. p. 1313.

[77] Lenz, Bot. der Alten, p. 560; Heldreich, Nutzpflanzen Griechenlands; Langkavel, Bot. der Späteren Griechen.

[78] Sprengel, Dioscoridis, etc., ii. p. 462.

[79] Olivier de Serres, Théâtre de l’Agriculture, p. 471.

[80] Bauhin, Hist. Pl., iii. p. 154.

[81] The best information about the cultivation of this plant was given by Bancroft to Sir W. Hooker, and may be found in the Botanical Magazine, pl. 3092. A. P. de Candolle published, in La 5^e Notice sur les Plantes Rares des Jardin Bot. de Genève, an illustration showing the principal bulb.

[82] Grisebach, Flora of British West-India Islands.

[83] Bertoloni, Flora Italica, ii. p. 146; Decaisne, Recherches sur la Garance, p. 68; Boissier, Flora Orientalis, iii. p. 17; Ledebour, Flora Rossica, ii. p. 405.

[84] Cosson and Germain, Flore des Environs de Paris, ii. p. 365.

[85] Kirschleger, Flore d’Alsace, i. p. 359.

[86] Willkomm and Lange, Prodromus Floræ Hispanicæ, ii. p. 307.

[87] Ball, Spicilegium Floræ Maroccanæ, p. 483; Munby, Catal. Plant. Alger., edit. 2, p. 17.

[88] Piddington, Index.

[89] Plinius, lib. 19, cap. 3.

[90] De Gasparin, Traité d’Agriculture, iv. p. 253.

[91] Columna, Ecphrasis, ii. p. 11.

[92] Linnæus, Hortus Cliffortianus, p. 420.

[93] A. de Candolle, Géogr. Bot. Raisonnée, p. 824.

[94] Schlechtendal, Bot. Zeit. 1858, p. 113.

[95] Decaisne, Recherches sur l’Origine de quelques-unes de nos Plantes Alimentaires, in Flore des Serres et Jardins, vol. 23, 1881, p. 112.

[96] Lescarbot, Histoire de la Nouvelle France, edit. 3, 1618, t. vi. p. 931.

[97] Pickering, Chron. Arrang., pp. 749, 972.

[98] Catalogue of Indiana Plants, 1881, p. 15.

[99] Boissier, Fl. Orient., iii. p. 745; Viviani, Fl. Dalmat., ii. p. 108; Bertoloni, Fl. Ital., viii. p. 348; Gussone, Synopsis Fl. Siculæ, ii. p. 384; Munby, Catal. Alger., edit. 2, p. 22.

[100] A. de Candolle, Géogr. Bot. Raisonnée, p. 671.

[101] Fraas, Synopsis Fl. Class., p. 196; Lenz, Bot. der Alten, p. 485.

[102] Willkomm and Lange, Prodromus Floræ Hispanicæ, ii. p. 223; De Candolle, Flore Française, iv. p. 59; Koch, Synopsis Fl. Germ., edit. 2, p. 488; Ledebour, Fl. Ross., ii. p. 794; Boissier, Fl. Orientalis, iii. p. 767; Bertoloni, Fl. Ital., viii. p. 365.

[103] Tournefort, Éléments de Botanique, p. 379.

[104] Gussone, Synopsis Floræ Siculæ.

[105] A. de Candolle, Géogr. Bot. Raisonnée, pp. 810, 816.

[106] Acosta, p. 163, verso.

[107] De l’Ecluse (or Clusius), Rariarum Plantarum Historiæ, 1601, lib. 4, p. lxxix., with illustration.

[108] De Martius, Flora Brasil., vol. x. p. 12.

[109] Von Humboldt, Nouvelle Espagne, edit. 2, vol. ii. p. 451; Essai sur la Géographie des Plantes, p. 29.

[110] At that epoch Virginia was not distinguished from Carolina.

[111] Banks, Trans. Hort. Soc., 1805, vol. i. p. 8.

[112] Gerard, Herbal, 1597, p. 781, with illustration.

[113] Banks, Trans. Hort. Soc., 1805, vol. i. p. 8.

[114] Dunal, Hist. Nat. des Solanum, in 4to.

[115] The plant imported by Sir John Hawkins and Sir Francis Drake was clearly the sweet potato, Sir J. Banks says; whence it results that the questions discussed by Humboldt touching the localities visited by these travellers do not apply to the potato.

[116] De l’Ecluse, Rariarum Plantarum Historiæ, 1601, lib. 4. p. lxxviii.

[117] Targioni-Tozzetti, Lezzioni, ii. p. 10; Cenni Storici sull’ Introduzione di Varie Piante nell’ Agricoltura di Toscana, 1 vol. in 8vo, Florence, 1853, p. 37.

[118] Solanum verrucosum, whose introduction into the neighbourhood of Gex, near Geneva, I mentioned in 1855, has since been abandoned because its tubers are too small, and because it does not, as it was hoped, withstand the potato-fungus.

[119] Chloris Andina, in 4to. p. 103.

[120] Sabine, Trans. Hort. Soc., vol. v. p. 249.

[121] No importance should be attached to this flavour, nor to the watery quality of some of the tubers, since in hot countries, even in the south of Europe, the potato is often poor. The tubers, which are subterranean ramifications of the stem, are turned green by exposure to the light, and are rendered bitter.

[122] Journal Hort. Soc., vol. iii. p. 66.

[123] Hooker, Botanical Miscellanies, 1831. vol. ii. p. 203.

[124] Journal of the Voyage, etc., edit. 1852, p. 285.

[125] Vol. i. part 2, p. 329.

[126] Vol. v. p. 74.

[127] Ruiz and Pavon, Flora Peruviana, ii. p. 38.

[128] Dunal, Prodromus, xiii., sect. i. p. 22.

[129] Hooker, Bot. Miscell., ii.

[130] Hooker, Fl. Antarctica.

[131] Journal Hort. Soc., new series, vol. v.

[132] Weddell, Chloris Andina, p. 103.

[133] André, in Illustration Horticole, 1877, p. 114.

[134] The form of the berries in S. columbianum and S. immite is not yet known.

[135] Hemsley, Journal Hort. Soc., new series, vol. v.

[136] Asa Gray, Synoptical Flora of North America, ii. p. 227.

[137] See, for the successive introduction into the different parts of Europe, Clos, Quelques Documents sur l’Histoire de la Pomme de Terre, in 8vo, 1874, in Journal d’Agric. Pratiq. du Midi de la France.

[138] Turpin gives figures which clearly show these facts. Mém. du Muséum, vol. xix. plates 1, 2, 5.

[139] Dr. Sagot gives interesting details on the method of cultivation, the product, etc., in the Journal Soc. d’Hortic. de France, second series, vol. v. pp. 450-458.

[140] Humboldt, Nouvelle Espagne, edit. 2, vol. ii. p. 470.

[141] Meyen, Grundrisse Pflanz. Geogr., p. 373.

[142] Boissier, Voyage Botanique en Espagne.

[143] Boyer, Hort. Maurit., p. 225.

[144] Choisy, in Prodromus, p. 338.

[145] Marcgraff, Bres., p. 16, with illustration.

[146] Sloane, Hist. Jam., i. p. 150; Hughes, Barb., p. 228.

[147] Clusius, Hist., ii. p. 77.

[148] Ajes was a name for the yam (Humboldt, Nouvelle Espagne).

[149] Humboldt, ibid.

[150] Oviedo, Ramusio’s translation, vol. iii. pt. 3.

[151] Rumphius, Amboin., v. p. 368.

[152] Forskal, p. 54; Delile, Ill.

[153] D’Hervey Saint-Denys, Rech. sur l’Agric. des Chin., 1850, p. 109.

[154] Study and Value of Chinese Botanical Works, p. 13.

[155] Thunberg, Flora Japon., p. 84.

[156] Forster, Plantæ Escul., p. 56.

[157] Hooker, Handbook of New Zealand Flora, p. 194.

[158] Seemann, Journal of Bot., 1866, p. 328.

[159] Roxburgh, edit. Wall., ii. p. 69.

[160] Piddington, Index.

[161] Wallich, Flora Ind.

[162] Roxburgh, edit. 1832, vol. i. p. 483.

[163] Rheede, Mal., vii. p. 95.

[164] Meyer, Primitiœ Fl. Esseq., p. 103.

[165] R. Brown, Bot. Congo, p. 55.

[166] Schumacher and Thonning, Besk. Guin.

[167] Wallich, in Roxburgh, Fl. Ind., ii. p. 63.

[168] Sloane, Jam., i. p. 152.

[169] Several Convolvulaceæ have large roots, or more properly root-stocks, but in this case it is the base of the stem with a part of the root which is swelled, and this root-stock is always purgative, as in the Jalap and Turbith, while in the sweet potato it is the lateral roots, a different organ, which swell.

[170] No. 701 of Schomburgh, coll. 1, is wild in Guiana. According to Choisy, it is a variety of the Batatas edulis; according to Bentham (Hook, Jour. Bot., v. p. 352), of the Batatas paniculata. My specimen, which is rather imperfect, seems to me to be different from both.

[171] Clusius, Hist., ii. p. 77.

[172] A. de Candolle, Géogr. Bot. Raisonné, pp. 1041-1043, and pp. 516-518.

[173] Dr. Bretschneider, after having read the above, wrote to me from Pekin that the cultivated sweet potato is of origin foreign to China, according to Chinese authors. The handbook of agriculture of Nung-chang-tsuan-shu, whose author died in 1633, asserts this fact. He speaks of a sweet potato wild in China, called chu, the cultivated species being kan-chu. The Min-shu, published in the sixteenth century, says that the introduction took place between 1573 and 1620. The American origin thus receives a further proof.

[174] Moquin-Tandon, in Prodromus, vol. xiii. pt. 2, p. 55; Boissier, Flora Orientalis, iv. p. 898; Ledebour, Fl. Rossica, iii. p. 692.

[175] Roxburgh, Flora Indica, ii. p. 59; Piddington, Index.

[176] Theophrastus and Dioscorides, quoted by Lenz, Botanik der Griechen und Römer, p. 446; Fraas, Synopsis Fl. Class., p. 233.

[177] Heldreich, Die Nutzpflanzen Griechenlands, p. 22.

[178] Alawâm, Agriculture nabathéenne, from E. Meyer, Geschichte der Botanik, iii. p. 75.

[179] Notice sur l’Amélioration des Plantes par le Semis, p. 15.

[180] Pohl, Plantarum Brasiliæ Icones et Descriptiones, in fol., vol. i.

[181] J. Müller, in Prodromus, xv., sect. 2, pp. 1062-1064.

[182] Sagot, Bull. de la Soc. Bot. de France, Dec. 8, 1871.

[183] I give the essentials of the preparation; the details vary according to the country. See on this head: Aublet, Guyane, ii. p. 67; Decourtilz, Flora des Antilles, iii. p. 113; Sagot, etc.

[184] R. Brown, Botany of the Congo, p. 50.

[185] Humboldt, Nouvelle Espagne, edit. 2, vol. ii. p. 398.

[186] Hist. de l’Acad. des Sciences, 1824.

[187] Guillemin, Archives de Botanique, i. p. 239.

[188] Acosta, Hist. Nat. des Indes, French trans., 1598, p. 163.

[189] Thomas, Statistique de Bourbon, ii. p. 18.

[190] The catalogue of the botanical gardens of Buitenzorg, 1866, p. 222, says expressly that the Manihot utilissima comes from Bourbon and America.

[191] Aypi, mandioca, manihot, manioch, yuca, etc., in Pohl, Icones and Desc., i. pp. 30, 33. Martius, Beiträge z. Ethnographie, etc., Braziliens, ii. p. 122, gives a number of names.

[192] Thonning (in Schumacher, Besk. Guin.), who is accustomed to quote the common names, gives none for the manioc.

[193] J. Müller, in Prodromus, xv., sect. 1, p. 1057.

[194] Kunth, in Humboldt and B., Nova Genera, ii. p. 108.

[195] Pohl, Icones et Descr., i. p. 36, pl. 26.

[196] Müller, in Prodromus.

[197] De Martius, Beiträge zur Ethnographie, etc., i. pp. 19, 136.

[198] Piso, Historia Naturalis Braziliæ, in folio, 1658, p. 55, cum icone.