FORMS OF THE PERIANTH. 



37 



it, as also do the parallel longitudinal seams. (See figs 68, 69.) 

 The labiate, bilabiate or lip-shaped, resembling the mouth of 

 some animal, is a very common form, resulting from the unequal 

 union of the parts, accompanied with other irregularities. In 

 the labiate corolla three petals unite more or less to form the 

 lower lip, and two to form the upper. In the calyx, when bila- 

 biate, this rule is reversed, according to the law of alternation 

 of organs ; two sepals are united in the lower lip and three in 

 the upper, as seen in the Sage and the Labiate Order generally. 

 Labiate flowers are said to be galeate or helmeted when the 

 upper lip is concave, as in Catmint ; ringent or gaping when the 

 throat or mouth is wide open (69) ; personate or masked when 

 the throat is closed as witli a palate, like the Snapdragon (70). 



104. Certain reduced forms of the perianth should be noticed 

 in this place. The Pappus (tfctfrros, grandfather, alluding to his 

 gray hairs) is the hair-like calyx of the florets of the Composite, 

 and other kindred Orders. The florets of this Order are col 

 lected into heads so compactly that the calyxes have not room 

 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. 



Agt 

 traV 



.Ji -la (incorrectly called achenium) of the Composite, with various forms of pappus. 72, Ecliptd 

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

 ata. > conizoides, pappus of five scales. 76, Mulgedium, capillary pappus cypsela slightly ros- 

 . 'A, Lactuca elongata, rostrate cypsela. 



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

 a mere rim, as seen in the Umbellifera3. In the Amentaceous 

 Orders, the whole perianth diminishes to a shallow cup, ;is in 



