PLANTS CULTIVATED FOR THEIR STEMS OR LEAVES. 117 



must be recent, for Roxburgh and Miquel do not men- 

 tion the species. In Ceylon it is only cultivated.^ 



On the whole, it seems to me that the probabilities 

 are in favour of an African origin, as its name indicates, 

 and this is confirmed by the general, but insufficiently 

 grounded opinion of authors.^ However, as the plant 

 spreads so rapidly, it is strange that it has not reached 

 Egypt from the Mozambique or Abyssinia, and that it 

 was introduced so late into the islands to the east of 

 Africa. If the co-existence of phanerogamous species 

 in Africa and America previous to cultivation were not 

 extremely rare, it might be inferred in this case ; but 

 this is unlikely in the case of a cultivated plant of 

 which the diflusion is evidently very easy. 



Article III. Various Uses of the Stem and Leaves. 



Tea Thea sinensis, Linnaeus. 



In the middle of the eighteenth century, when the 

 shrub which produces tea was still very little known, 

 Linnoeus gave it the name of Thea sinensis. Soon after- 

 wards, in the second edition of the Species Plantatum, 

 he judged it better to distinguish two species, Thea hohea 

 and Thea viridis, which he believed to correspond to the 

 commercial distinction between black and green teas. It 

 has since been proved that there is but one species, com- 

 prehending several varieties, from all of which either 

 black or green tea may be obtained according to the pro- 

 cess of manufacture. This question was settled, when 

 another was raised, as to whether Thea really forms 

 a genus by itself distinct from the genus Camellia. 

 Some authors make Thea a section of the old genus 

 Camellia ; but from the characters indicated with great 

 precision by Seemann,^ it seems to me that we are 

 justified in retaining the genus Thea, together with the 

 old nomenclature of the principal species. 



A Japanese legend, related by Ktempfer,^ is often 



* Baker, Fl. of Mauritius and Seychelles, p. 436. 



* Thwaites, Enum. PL Zeylanice. 



' Seeoiann, Tr. of the Linncean Society, xxii, p. 337, pi. Gl. 



* KaempfLr, Ammn. Japan. 



