NATURAL ORDERS. 109 



natia, whose place in the system is, indeed, not yet deter- 

 mined, btit of which the habit is nearly that of Rhodoleena, 

 seems in some degree to confirm M. du Petit Thouars's 

 opinion of the near relation of Chlenacese to Tihacese ; though 

 M. de Jussieu, in placing it between Ebenacese and Rho- 

 doracese,^ appears to take a very different view of its 

 affinities. 



M ALVACE^. Of this family 1 8 species were observed 

 on the banks of the Congo. It forms, therefore, about one 

 thirty -fourth part of the phsenogamous plants of the collec- 

 tion ; which is somewhat greater than the equinoctial pro- 

 portion of the order, as stated in Baron Humboldt's disser- 

 tation,^ but nearly agrees with that of India, according to 

 Dr. Roxburgh's unpublished Flora Indica. 



The greater part of the Malvaceae of the collection belong 

 to Sida and Hibiscus ; and certain species of both these 

 genera are common to India and America. TJrena Ameri- 

 cana and Malachra radiata, hitherto supposed to be natives 

 of America only, are also contained in the collection ; and [439 

 the loftiest tree seen on the banks of the Congo, is a species 

 of Bombax, which, as far- as can be determined from the 

 very imperfect specimens preserved in the herbarium, does 

 not differ from Bombax pentandrum of America and India. 

 I have formerly remarked^ that Malvaceae, Tiliacese, Her- 

 manniacese, Buttneriacese, and Sterculiacese, constitute one 

 natural class ; of which the orders appear to me as nearly 

 related as the different sections of Rosacese are to each 

 other. In both these, as well as in several other cases 

 that might be mentioned, there seems to be a necessity for 

 the establishment of natural classes, to which proper names, 

 derived from the orders best knowiij and differing perhaps 

 in termination, might be given. 



It is remarkable that the most general character connect- 

 ing the different orders of the class now proposed, and which 

 may be named from its principal order Malvaceae, should 



1 Mirbel, Mem,, de Physiol. Teg. et de Bot. 2, p. 855. 



^ Prolegomena, p. xviii. Be Dhirib. Geogr. Plant., p. 43. 



3 Flinders' s Voy. 2, p. 540. {Ante, p. 11.) 



