i PREFACE. 



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

 ;o 757. The perianth being tubular, and bent in form ot 

 m S, etc., we decide that it is Aristolochia. 



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

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

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

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

 ng there that this sedge is not monoecious nor dioecious, 

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

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

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

 'ichium, spathaceum, Nees. 



To identify the very last plant, we were directed from 

 )39 to 540. As it is not grass-like, we proceed to 541. 

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

 [t being further no maritime plant, we apply to 544, 

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

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

 jedded) flowers, always three together, forming chib- 

 ihaped spikes, etc., we ascertain that it is SaUcomia. 



The young botanist, after having a few times used the 

 key, wiU be aware tliat it is not always necessary to begin 

 in 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 asldng : Are there more or 

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

 see fit 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 

 the chief divisions, namely : 



