ASH : AILANTHUS 101 



of fertilization of a single flower, the apocarpous pistils of 

 which have developed into achenes, each topped by the 

 persistent style that has grown out into a plumose fila- 

 ment. The only similar arrangement in our flora exists 

 in certain herbaceous Anemones and Potentillas. 



tt Fruits not aggregated in heads, catkins, &c. 



Fruit a samara, winged by forward or[For(0C 

 lateral p-olongation of the carpel into a see P- 1( ^3 



l~~l Wing long and narrow, prolonged forwards 

 only, with the seed at its base. 



Fraxinus excelsior, L. Ash (Fig. 18). Winged fruit 

 about 40 x 8 mm. ; the wing leathery, smooth, tawny, 

 cuneate-oblong rounded above, with numerous more or 

 less parallel veins ; seed nearly half as long as the whole 

 fruit, flat, cuneate-oblong, longitudinally striate. Pedicel 

 and remains of floral axis present at the base. 



OO Wing prolonged in more than one 

 direction, with the seed near the middle. 



Wing elongated, asymmetrical, notched 

 on one side near the middle. 



Ailanthus glandulosa, Desf. Tree of Heaven (Fig. 19). 

 The fruit is about 25 x 10 mm. long, flat, thin, tawny, and 

 irregularly oblong and veined : the lateral notch is due to 

 lack of growth at the point of attachment of the seed. 

 The wing is usually twisted above. Each flower gives 

 rise to several, about three, fruits. 



Wing broad oval to sub-orbicular, 

 notched at the top ; remains of peri- 

 gone persisting below. 



$ Seed in the middle of the broadly 

 oval samara. 



Ulmus montana, Sm. Wych Elm (Fig. 98). Fruit 



