350 



HUTCHINSON'S POPULAR BOTANY 



FIG. 430. FIGWORT, 



With sub-globose corolla. Adapted 

 for pollination by wasps. 



and this is effected in a beautiful manner. The 

 petals become detached at their base, and curl up 

 spirally that is to say, towards their common point 

 of attachment at the apex of the flower ; and in 

 this condition they remain till, by the expanding 

 of the stamens, they are thrown off completely. 



A more interesting, because more intricate, 

 form of irregular flower than any which we have 

 yet considered is that which constitutes the 

 characteristic feature of the well-known and 

 extensive sub-order of Legumiiiosse, to which 



the Pea and Bean belong namely, Papilionacese. This name at once 

 suggests the form of the corolla, which Tournefort and Ray, and the early 

 botanists generally, conceived to bear a resemblance to a butterfly with 

 expanded wings. Papilio is the Latin word for ' butterfly," and hence the 

 corolla came to be called papilionaceous and the sub-order Papilionaceae. 

 But it was reserved for a modern philosopher to advance the startling 

 suggestion that possibly the first butterflies were flowers "which got loose 

 from their stalks and flew away " ! Papilionaceous flowers are pollinated 

 almost exclusively by bees, to which the several parts of the corolla bear 

 the most evident relation. The reproductive organs (stamens and pistil) are 

 contained in the two inferior petals (fig. 428), which cohere to form the keel 

 or car-ilia (cc), the latter an excellent contrivance for protecting the anthers 

 from pollen-feeding insects and from rain. The lateral petals (a a) known 

 as the wings or aloe, besides affording a platform for bees, serve as a lever 

 to depress the keel, as well as to bring it back to its place after depression, 

 if repeated insect-visits are necessary for pollination. Lastly, the large 

 posterior petal, which is known as the standard 

 or vexillum (v), gives conspicuousness to the 

 flower, as well as closes the entrance to the 

 nectary from behind, so that insects seeking honey 

 must sit either on the keel or wings. 



We must not conclude these remarks upon 

 the forms of calyxes and corollas without some 

 reference to composite Row GIB A composite flower 

 is really a number of florets crowded together on 

 a single base or receptacle, such as we find, for 

 instance, in the flower-head (capitulum) of a Daisy 

 (BMis perennis) or Dandelion (Taraxacumofficinale). 

 We have chosen for illustration the flower-head 

 of a Chrysanthemum (C. carinatuTri), the florets 

 of which are more easily distinguished than are 

 those of the commoner flowers above named. 

 What you see (fig. 433) is a section, the flower- 



FIG. 431. HISPID HEATH. 



Complete flower (upper), and the same 

 after removal of calyx and corolla, to 

 show position of stamen* and pistil. 



