246 OKGANOGEAPHY. 



tion, and several terms are in common use to indicate such 

 variations. 



In the first place, certain names are applied to define the 

 number of the stamens when compared in this respect with the 

 sepals and petals. Thus when the stamens are equal in number 

 to the sepals and petals, the flower is said to be isostemenous, as 

 in the Primrose; if they are unequal, as in the Valerian, the 

 flower is cmisostemenous ; or when greater accuracy is required 

 in the latter case, we say dij^lostemeJious, if the stamens are 

 double the number, as in Stonecrop, meiostemenotis, if less in 

 number, as in the Lilac, and 'polystemenous, if more than double, 

 as in the Kose. 



Second]}'-, the flower receives different names according to 

 the actual number of stamens it contains, without reference to 

 til e number of parts in the outer whorls. This number is in- 

 dicated by the Greek numerals prefixed to the word androus, 

 which means male or stamen. Thus : — 



A flower having One stamen is Monandrous, as in the Mare's 



Tail and Eed Valerian. 

 ,, „ Two stamens is Diandrous, as in the Ash and 



Privet. 

 ,, „ Three stamens is Triandrous, as in the Iris 



and most Grasses. 

 „ „ Four stamens is Tetrandrous, as in the Holly 



and Rib-grass. 

 „ ,, Five stamens is Pentandrous, as in the Cows- 

 lip and Henbane. 

 ,, „ Six stamens is Hexandrous, as in the Lily and 



Tulip. 

 ,, „ Seven stamens is Heptandrous, as in the Horse 



Cliestnut and Chickweed Winter-green. 

 „ ,, Eight stamens is Octandrous, as in the lA-y and 



Heath. 

 ,, „ Nine stamens is Enneandrous, as in the Flower- 

 ing Rush and Rhubarb. 

 „ „ Ten stamens is Decandrous, as in the Pink and 



Saxifrage. 

 „ „ Twelve stamens is Dodecandrous, as in the 



Asarabacca and Purple Loose-strife. 

 „ ,, Twenty stamens is Icosandrous, as in the 



Strawberry. 

 „ ,, Numerous stamens is Polyandrous, as in the 



Poppy and Water-Lily. 



We shall have to refer to these terms again when treating of 

 the Linnsean system of classification, as many of the classes in 

 that system are determined by the number of stamens con- 

 tained in the flower. 



