37, 38.] 



FORMS OF THE PERIANTH. 



45 



for expansion in the ordinary way. The pappus is 

 commonly persistent, and often increases as the fruit 

 matures, forming a feathery sail to waft away the 

 seed through the air, as in the Dandelion and Thistle. 

 It varies greatly in form and size, as seen in the cuts ; 

 sometimes consisting of scales, sometimes of hairs, 

 again of feathers or bristles. Sometimes it is mounted 

 on a stipe, which is the beak of the fruit. 



Cypsela (incorrectly called akenium) of the Composite, with various forms of pappus. 72, Ecripta 

 procumbens, no pappus. 73, Ambrosia trifida. 74, Helianthus grosse-serratus, pappus 2-awned. 75. 

 Ageratum conizoides, pappus of five scales. 76, Mulgedium, capillary pappus cypsela slightly rostrate. 

 "7, Lactuca elongata, rostrate cypsela. 



105. Again : the calyx, or the limb of the calyx, is 

 reduced to a mere rim, as seen in the Umbelliferse. 

 In the Amentaceous Orders, the whole perianth di- 

 minishes to a shallow cup, as in the Poplar and Wil- 

 low, or altogether disappears, as in the Birch, Ash, 

 and Lizard-tail (15, 16). 



106. Setae, meaning bristles in general, is a term 

 specifically used to denote the reduced perianth of the 

 sedges. In the Bog-rush (Scirpus) there is, outside the 

 stamens, a circle of six setae, representing a 6 -leaved 

 perianth (78). In the Cotton-grass (Eriophorum) the 

 setae are multiplied and persistent on the fruit, becom- 

 ing long and cotton-like. 



107. Perigynium is the name given to the urceo- 

 late perianth of Carex, investing the ovary, but allow- 

 ing the style to issue at its summit. It is composed 





