518 



STRUCTURE OF FLOWER OF ORCHIDE^E. 



in this order, whilst its form is slender. This contains but one 



cell, having three parietal 

 placentas, from each of 

 which arise a great num- 

 ber of ovules. On ex- 

 amining the leafy parts of 

 the flower, they are seen 

 to be six in number, very 

 irregularly disposed. The 

 three external ones, which 

 are considered as the 

 sepals of the calyx, are 

 seen in the adjoining 



FIG. 188. A, FLOWER OF SPIDER ORCHIS, much figure (A) pointing UD- 

 enlarged; B, ADHERENT ANTHER AND STIGMA, much ' , 



enlarged. wards and to the sides ; 



the two lateral ones in 



some species rise towards each other, and even meet and adhere, 

 forming a sort of helmet-shaped arch, from beneath which the 

 other parts of the flower project. The petals are also three, one 

 of them being very much larger than the other two ; the two 

 small ones are seen in the figure to point upwards and outwards, 

 alternating with the sepals ; whilst the large one, pointing 

 directly downwards, is that which has the greatest variety of 

 form and colour in the different species, giving rise, by its curious 

 metamorphoses, to the strange resemblances already alluded to. 

 At the upper part of this transformed petal, which is termed the 

 IdbeHum or lip, is an opening that leads in many of the species 

 to a long spur that projects below. The other leafy portions of 

 the flower are, in general, very delicately-coloured on their in- 

 terior side. So far, the structure of the flowers is not very diffi- 

 cult to understand, except in a few species in which the trans- 

 formation is carried much farther. 



694. The most remarkable peculiarity of the Orchideae, 

 however, consists in that modification of the special organs of 

 fructification, to which Linnaeus gave the name of gynandrous, 

 and upon which he founded his twentieth class ; and, as this is 



