350 



A TEXTBOOK OF BOTANY 



[Ch. VII, 2 



Fig. 243. — Ripen- 

 ing ovary of Buckej^e, 

 showing development 

 of one of the six ovules. 

 (After Gray.) 



so-called pappus, a structure on the ovary usuallj' interpreted 

 as morphologicalljr calyx, persists as hooks, plumes, and 

 other analogous structures (Fig. 256). Furthermore, wholly 

 new structures also develop from the ovary 

 wall, usually in obvious adaptation to 

 dissemination. Thus many small weeds 

 develop hooks or adhesive glands, making 

 their "seeds" cling tight to the clothing 

 of the stroller in autumn fields. Very 

 jDrominent arc the fiat wings which de- 

 velop on the Maple (Fig. 245), the Elm, 

 and the Ash. 



Fleshy fruits also exhibit, though less 

 clearly, the signs of their origin from ovaries. They possess 

 two features not found in dry fruits, — viz. bright and con- 

 trasting colors, and seeds which are usually protected in 

 some way against injurj^ by digestion when eaten ; for, as 

 will appear in the following section, 

 fleshy fruits are eaten and their seeds 

 thus disseminated by animals. The 

 simplest fleshy fruit is the berry, in 

 which the wall of the ovary, whether 

 carpels or receptacular cup, develops 

 into the pulp, while the seeds have 

 stony coats, as well exemplified in 

 the Grape, and also in Cranberry and 

 Blueberry. Closely related is the 

 stone fruit, or drupe, wherein the 

 outer layers of the ovary wall ripen 

 to the soft pulp, while the inner layers 

 form the hard stone, which consti- 

 tutes the most effective protection to 

 the seed, as so typically illustrated in 

 the Cherry, the Plum, or the Peach (Fig. 24(i). The fruits 

 just mentioned, by the way, show on one side a depressed 

 line which indicates the original joining of the edges of the 



Fig. 244. — Fruit of Clema- 

 tis. (From Bailey.) 



