ORDER POLYANDRIA. 
177 
Fig 140, a, is a flower of the genus Geranium. The three families, 
Erodium, Pelargonium, and Geranium, were, formerly, all united 
in one genus ; but the difference in the number of stamens seems 
decidedly to separate them, not only into different genera, but 
different orders. 
Order Polyandria. 
The thirteenth Order (many stamens) is made up entirely of a 
group of genera which compose the natural order Columnifer-'E of 
Linneeus ; the stamens are united in the form of a column, (see 
Fig. 140, h ;) by Jussieu they have been collected into an order, 
under the name of Malvacem, so called from the genus Malva. 
The pecuhar 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 j 
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, (Gossypium.') The Ckmeiak 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 lavatera, 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 circum- 
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 v/hich was inscribed the date of the fourteenth, and upon the 
other that of the fifteenth century ! yet 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 Polyandria— Columniferae— Plants which compose this family— Plants of this 
class \ariable in size — Adansonia. 
