44 STRUCTURAL BOTANY. [36, 37. 



cylindraceous form spreading little or none at the bor- 

 der ; as the calyx of the Pink, corolla of the Honey- 

 suckle. It is often a little curved. Tubular flowers 

 are common in the Compositae, as the Thistle, Sun- 

 flower, when they are often associated with the next 

 form, the ligulate. 



103. Gamopetalous - irregular perianths may be 

 either ligulate or labiate. The ligulate corolla (ligula, 

 tongue) is formed as if by splitting a tubular corolla 

 on one side. The notches at the end plainly indicate 

 the number of united petals composing 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, result- 

 ing 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 bilabiate, 

 this rule is reversed, according to the law of alterna- 

 tion 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 with a palate, like the Snap- 

 dragon (70). 



104. Certain reduced forms of the perianth should 

 be noticed in this place. The Pappus (ndTnros, grand- 

 father, alluding to his gray hairs) is the hair-like calyx 

 of the florets of the Compositse, and other kindred 

 Orders. The florets of this Order are collected into 

 heads so compactly that the calyxes have not room 



