ORDER POLYANDRIA. i^T 



Fig 140, a, is a flower of the genus Geranium. The three famiUes, 

 Erodium, Pelargonium, and Geranium, were, formerly, all united 

 in one genus ; but the difference in the number of stamens seem^ 

 decidedly to separate them, not only into different genera, but 

 dilferent orders. 



Order Pobjandrla. 



The thirleenlh Order (many stamens) is made up entirely of a 

 group of genera which compose the natural order Columnifer.'k o^ 

 Liniiffius ; the stamens are united in the form of a cohmw, (see 

 Fig. 140, b ;) by Jussieu they have been collected into an order, 

 under the name of Malvacece, so called from the genus Malva. 

 Tlie peculiar characteristics of the whole group are, a calyx often 

 double, 5 regular petals, stamens numerous, united by their fila- 

 ments into a tube, and rising like a column in the centre of the flow- 

 er ; in the centre of this tube are the styles, forming an inner bundle ; 

 the number of these is various, though often found to be eight. The 

 number of seed vessels, each of which contains one seed, equals 

 the number of styles ; these are arranged in a circle. Among the 

 plants which compose this family, are the hollyhock, the mallows, 

 and the cotton, [Gossypimn.) The C amelia japonica, or Japan rose, 

 a very splendid flower, equal in size to the largest rose, is found 

 here. The rich colouring of its corolla contrasts beautifully with 

 its dark green leaves. 



Most of the native species of the class Monadelphia may easily 

 be procured for analysis, in the season of flowers. The hollyhock 

 is in almost every garden ; the common mallows grows wild about 

 dwellings ; the lava'tera, a hardy and cheerful-looking plant, though 

 an exotic, spreads with great rapidity over our gardens and shrubbe- 

 ries. 



The plants of this class vary in size, from the low mallows to some' 

 of the largest trees that have yet been discovered ; " the Silk cotton 

 tree (Bombax pentandrum) is so large, and spreads its branches so 

 widely, that twenty thousand persons might stand under them. This 

 tree is a native of Africa and America. The Adansonia, a native 

 of Senegal in Africa, is said to grow to the size of 70 feet in circunv 

 ference ; this tree also attains great age. In 1749, the learned Adan- 

 son saw two of these trees in the neighbourhood of Gorrea, upon one 

 of which was inscribed the date of the fourteenth, and upon the 

 other that of the fifteenth century ! j^et there were good reasons to 

 suppose that the trees were not young when the dates were cut. It 

 may be conjectured that they have sometimes attained to the age of 

 eight or nine hundred years! an immense period of time for the 

 existence of any species of organized bodies."* 



Having now considered the Class Monadelphia in its most impor- 

 tant particulars, we will pass to the next class, which, in common 

 with this, is founded upon the union of the filaments. 



♦ B. S. Barton. 



Order I'o'.yandria—ColumniferBe— Plants which compose this family— Plants of thiij 

 class variable in size — Adansonia. 



