▼i PREFACE. 



to 755. As the ovary is under the perianth, we pass on 

 to 757. The perianth being tubular, and bent in form of 

 an S, etc., we decide that it is ArUtoloehia. 



As the last two plants of our half dozen have no peri- 

 anth at all, or only a few bristles supplying its place, 

 we are from 539 directed to 540, where we learn that one 

 of them is a sedge. Being directed to 551, and ascertain- 

 ing there that this sedge is not monoecious nor dioecious, 

 we pass on to 552. The glumes being two-rowed, we 

 apply to 553, where, as our sedge has its spikes on soli- 

 tary, axillary peduncles, etc., we verify that it is Du- 

 lichium spathaceum, Nees. 



To identify the very last plant, we were directed from 

 539 to 540. As it is not grass like, we proceed to 541. 

 It being not a stemless or scapeless plant, we pass on to 542. 

 It being further no maritime plant, we apply to 544, 

 where, as it is a leafless, succulent, fleshy plant, with a 

 jointed stem, and closely appressed (or, as it were, im- 

 bedded) flowers, always three together, forming club- 

 shaped spikes, etc., we ascertain that it is Salicoriiia. 



The young botanist, after having a few times used the 

 key, will be aware that it is not always necessary to begin 

 an investigation on the first page. First of all, he must, 

 whenever a phaenogamous plant is to be identified, begin 

 with the questions : Are there several flowers in a com- 

 mon involucre, and, if so, are the anthers united ? Then : 

 Are the flowers diclinous? These questions answered in 

 the negative, he will continue asking : Are there more or 

 less than 20 stamens in each flower ? In most cases he will 

 see tit to start at once from § 77. 



After having some practice in using the key, the student 

 will be capable of at once attacking one or the other of 

 tbe chief divisions, namely : 



