CHAPTER XV. 



TYPES OF FLOWER. 



Simplest types -Yew Juniper and Cypress Pine, Fir, Larch and 

 Cedar Cones Gymnospermy Angiosperms Willows and 

 Poplars Achlamydeous Flowers Unisexual Flowers Birch, 

 Alder and other Catkinate Trees Chestnut Husk or Cupule 

 Oak, Beech, &c. More highly specialised Flowers Hypogynous 

 Flower of Buttercup and Clematis Discifloral Flower of Maple 

 Disc Rosaceous Type Passage from perigyny to epigyny 

 Leguminous and Papilionaceous Type Gamosepaly and Zygo- 

 morphy Ericaceous Type Gamopetaly Caprifolicious Type 

 Epigyny, &c. 



IT will now be advisable to fix our ideas, fortified with 

 the preceding details, on the structure, symmetry, and 

 comparative morphology of the flower and its parts, by 

 describing certain selected types of flower such as are 

 illustrated by the trees and shrubs here to be dealt with. 

 One of the simplest of all flowers is that of the Yew. 

 On some of the Yew-plants we find the flower consists 

 simply of a short axis bearing about three decussate pairs 

 of opposite scales and terminating in an ovule, which is 

 completely exposed (naked) except for a loosely investing 

 fleshy cup, known as the aril (Figs. 28 and 46). Here then 

 we have the flower reduced to its simplest possible elements; 

 a single ovule, with a few investing scales. It looks so 

 like an ordinary green bud at the time of flowering that 



