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.,
