

HOW TO USE THE KEY AND THE FLORA. XI 



that it is Polypetalous. As the stamens are very numerous it 

 must come under the section marked A. Under this section 

 we have three subordinate headings, marked by one, two, and 

 three asterisks, respectively. The stamens are clearly inserted 

 on the calyx, and so our plant must be found under the 

 heading marked **. Without hesitation, we refer it to the 

 Order ROSACES. Turning to page 38, we find fourteen 

 Genera to select from. A very little consideration will show 

 us that No. 8, FRAGAKIA, is the Genus we must fix upon. 

 Referring to page 43, we have to choose between two species, 

 Viryiniana and vesca, and the choice is found to depend upon 

 such obvious characters as to furnish no difficulty. 



The leaves of Blue Flag are straight-veined ; the parts of the 

 flower, also, are in threes. We therefore decide that the 

 plant is Monocotyledonous, and on turning to page xxii, we 

 find three Divisions of Monocotyledons. The Flag clearly 

 belongs to the PETALOIDEOUS DIVISION. Then, is the peri- 

 anth superior or inferior ? Clearly the former. Next, are the 

 flowers dioecious or perfect ? Clearly perfect. And as the 

 flower has three stamens, it must belong to the Order 

 IRIDACE^, described on page 155. The Genus is at once seen 

 to be IRIS, and the Species is determined without difficulty. 



The Cat-tail Flag is also manifestly Monocotyledonous, from 

 the veining of the leaves. But it is not Petaloideous. The 

 flowers are collected on a more or less fleshy axis at tho top 

 of a scape. It therefore belongs to the SPADICEOUS DIVISION, 

 in which there are four Orders. The only practical question 

 is, whether our plant belongs to ARACE^E or TYPHACE^E. On 

 the whole, we choose the latter, and find our decision con- 

 firmed on reading the fuller account of the two Orders on 

 pages 143 and 144. The Genus is immediately seen to be 

 TYPHA, and the Species latifolia. 



These examples need not be extended here ; but the 

 beginner is recommended to run down, in the same manner, a 



