° c <- l " 1 • H. TAKEDA.-—ON THE GENUS ACHLY8. 17;, 



bearing a few flowers is occasionally produced at the very base 

 of the spike, and this short branch is subtended by a minute 

 scaly bract (pi. VII, figs. 7-8, and text-fig. Ill, 2-3). This 

 phenomenon, so far as the writer is aware, does not occur in 

 A. triphylla. This short branch is, as a matter of fact, a small 

 pleiochasium, known to occur in many other members of this 

 family. Sometimes it is very much reduced and is represented 

 by a single flower, or even b}' a rudiment of a flower borne in 

 the axil of a bract (cf. text-fig. Ill, 5). This pleiochasium, whe- 

 ther well developed or reduced to a single flower, is, as a rule, 

 situated at some distance from the main spike. In some cases, 

 however, especially when represented by a single flower, it 

 may be found quite close to the main spike. Such a flower 

 can be distinguished from the rest by the presence of the sub- 

 tending seal}' bract. If this bract were reduced to nothing, there 

 would be no means of recognising a flower of this nature. 



It may not be out of place to mention here that the de- 

 velopment of the flowers on the main spike is acropetal, so that 

 when the basal flowers are fully open the apical ones are still 

 in bud. Thus, Tischler (18, p. 682), based on Calloni's in- 

 vestigation, distinguishes three regions in a spike : 



1. The flowers at the base of the spike — the stamens are 

 more or less withered, the anthers have dropped or are without 

 pollen, and the ovule is ready for fertilization; 



2. The flowers of the middle region — the stamens are mature, 

 the ovule has not yet attained the fertilization-stage ; and 



3. The flowers of the apical region — the anthers are still 

 hidden, the ovule has not yet assumed the anatropous position, 

 and the embryo-sac is not mature. 



Knuth (12, p. 61), on the other hand, gives an extraordinary 

 account of the flowers, and says that the lower ones are barren, 

 the middle are in part fertile, and the upper are all fertile. This 

 statement, although derived from the same source as Tischlkk's 

 seems to be due to a misunderstanding of the original and is 

 certainly incorrect. 



