PRACTICAL APPLICATION OF THE LINN^EAX SYSTEM. 377 



papilionaceous form of corolla, which, on being appreciated, will, in the great majority 

 of instances, alone suffice to indicate the class. Lastly, when the stamens are united 

 together by their filaments, as above indicated, but cannot be divided into distinct 

 bodies, as in the Geranium and Mallow, the plant is Monodelphous. 



There may, perhaps, be some little difficulty to the young botanist in determining 

 whether plants belonging to the Monodelphian and Polydelphian classes have really 

 their filaments so united ; but a very little attention and practice will show that the 

 filaments are not separate on both sides down to their base, and, moreover, the 

 characteristic appearance of the stamens as a whole will soon be appreciated by the 

 student. 



If the filaments be free, but the stamens united together, the plant will belong to 

 the order Syngenesia ; but as all this great class of plants have aggregated florets placed 

 as a capitulum (Figs. 354, 355), their appearance is so characteristic, that, after a very 

 short space of time, the student will not need to examine the stamens to determine the 

 classification of the plant. 



The only other exceptional class is that of Gynandria ; and it is not one which can 

 be very intelligibly described upon paper. It is composed of the Orchis tribe of plants, 

 and those closely associated with it ; and if the student will regard attentively the 

 combined stamens and pistils, and the toute ensemble of the flower of any Orchis, as of 

 those growing in our moist meadows, or those now universally found in hot-houses, he 

 will speedily learn how to distinguish this class in an instant, without, however, being 

 so readily able to explain it to another. 



We have considered the foregoing exceptional cases first, not because they are the 

 most numerous in the great assemblage of plants, but because they have readily 

 recognised characteristic peculiarities, and because, having excluded them from con- 

 sideration, the student may give undivided attention to the greater number which yet 

 remain. If the stamens are free from each other throughout, and are nearly of equal 

 size (differing somewhat according to the progressive development of the season), and 

 are not more than ten in number, the plant may be at once referred to its proper class, 

 as Monandria, &c. ; but if the number should be indefinite say fifteen, or any larger 

 number the plant may be either Icosandrous or Polyandrous. To determine to which 

 of the two classes it is to be referred, simply tear away the corolla and calyx piece by 

 piece ; and if the stamens come away with the pieces as would be the case in the 

 Rose, Hawthorn, and Apple the plant is Icosandrous. This indicates that the stamens 

 are Epigynous ; whilst the Hypogynous mode of insertion is characteristic of the class 

 Polyandria. The Eose may illustrate Icosandria, and the Crow-foot (Ranunculus) 

 Polyandria. 



The small class of Dodecandria is not so easily recognised by its stamens, since the 

 number is considerable, but somewhat indefinite. 



The foregoing directions will suffice as a guide to the student, except in the com- 

 paratively few instances in which the number of stamens has been unduly increased or 

 diminished. The increase is less common than the decrease ; and is chiefly restricted 

 to the classes Triandria and Pentandria, or all the classes below Pentandria, and is 

 usually to the extent of a duplicate of the original number. Thus a Triandrous plant 

 occasionally has six stamens, and a Pentandrous one has ten stamens. This little diffi- 

 culty is overcome by examining other flowers on the same plant, or on a similar plant 

 growing near to it, when the normal number af stamens will be found on a majority of 

 thorn. 



VOL. II, N 



