APPENDIX A 609 



illustrate a primitive state of this epigynous type where all the parts of 

 perianth and androccium are separate. A more advanced type, showing 

 not only epigyny but also cohesion of the perianth, and adhesion of the 

 stamens to it, is seen in Narcissus. 



(4) In the Daffodil (A*. Pseudo-Narcissus, L.), the same floral diagram 

 (Fig. 455) and floral formula apply. But here the coherent perianth springs 

 from the summit of the inferior ovary as a tube which separates upwards into 

 six widely spreading segments. At the level where they diverge the tube 

 appears to be continued into a wide trumpet-shaped corona. This is an 

 accessory formation, and only appears late, after the other parts have been 

 formed. From the inner surface of the perianth-tube, near to its base, arise 

 the six epiphyllous stamens. They are closely grouped round the central style, 

 whose stigma projects beyond them. Honey-secretion is provided by three 

 deep glands in the septa of the ovary, and it flows into the base of the tube. 

 The size of the flower allows entry to humble-bees, which, passing from flower 

 to flower, make cross-pollination probable. 



Narcissus poeticus, L., the Pheasant's Eye, is a species of similar construction, 

 but with white perianth, and a corona fringed with red. Its tube is, however, 

 narrow, and the anthers and stigma almost fill its opening. Thus it is inacces- 

 sible to bees ; but its white colour, heavy scent, and the length of the narrow 

 tube fit it for pollination by long-tongued, night-flying moths. These three 

 types of Amaryllids show how the same floral structure may be modified as a 

 mechanism for pollination by different types of insects. 



The Amaryllidaceae are less numerous in genera and species than the 

 Liliaceae, but are widely spread, especially in the Mediterranean region, and 

 at the Cape. They include many bulbous plants, and some that yield fibres 

 (Agave). 



Family : Iridaceae. Example : Yellow Flag. 



(5) Those Liliales which have inferior ovary and only three stamens, are 

 grouped as the Iridaceae, of which the native Yellow Flag (Iris Pseudacorus, L.) 

 serves as sdi example. It has a branched and strongly rooted perennial 

 stock (see Fig. 129, p. 196) and each branch ends in an annual foliage-shoot, 

 with sword-shaped leaves, sheathing at the base. The apex of certain shoots 

 extends upwards into the cylindrical flowering stems, which bear their first 

 flower distally ; a second flower arises subsequently in the axil of a bract 

 below it, and others may follow, in sympodial arrangement. 



The large yellow flower is composed of the following parts (Fig. 458) : 



Perianth, segments 3+3, gamophyllous at the base, superior ; the outer 



series broad and recurved, the inner narrower, and erect. 

 Androecium, stamens 3+0, free, epigynous, anthers opening outwards. It 



is the inner series that is absent. 

 Gynoecium, carpels 3, syncarpous, styles three petaloid ; ovary inferior, 



trilocular with axile placentation ; ovules numerous, anatropous 



(Fig. 213, p. 291). 



The fruit is a dry loculicidal capsule, and the flattened albuminous seeds are 

 scattered by the wind. 



Pollination. The flower of Iris is more specialised in relation to insect- 



