EXPLANATION OF THE PLATES. XXV 



PLATE XXI. 



A. Butomus umbellatus, Linncsus : p. 125. 



1. A flower with the perianth removed. 



2. One of the carpels. 



3. A transverse section of the carpels. 

 B. Typha latifolia, Linnceus : p. 121. 



1. A male flower, separate. 



2. A female flower, separate. 



C. Acorns Calamus, Linnaeus : p. 123. 



1. A flower with its green scales and stamens, and broad 



sessile stigma. 



2. One of the scales with its accompanying stamen, sepa- 



rate. 



3. An ovary. 



D. Potamogeton natans, Linnaus : p. 123. 



1. One of the flowers. 



2. A stamen, separate. 



3. One of the carpels. 



E. Lemna trisulca, Linnceus : p. 122. 



1. A frond with its branches and root. 



2. A flower. 



F. Juncus effusus, Linn&us : p. 124. 



1. A portion of the cylindrical stem. 



2. A flower. 



3. A capsule with the dry persistent perianth. 

 Q. f Carex riparia, Curtis : p. 129. 



1. A flower of the male spikelet with its glume. 



2. A flower of the female spikelet with its glume. 



PLATE XXII. 



A. Arundo Phragmites, Linnaeus : p. 131. 

 1. One of the flowers, separate. 



