FRUIT. 
79 
205 
Nut and Cupule. 
That they are not seeds is plain from the way they are produced, and from their 
bearing a style or stigma, at least when young. They are evidently pistils ripened ; 
and on cutting them open, the seed is found whole within (Fig. 204). 
230. A Grain (or Caryopsis) is the same as an akene, except that the thin seed- 
vessel adheres firmly to the whole surface of the seed. Indian corn, 
wheat, rye, and all such kinds of grain are examples. 
231. A Nut is a hard-shelled, one-seeded, indehiscent fruit, like an 
akene, but on a larger scale. Beechnuts, chestnuts, and acorns (Fig. 
205) are familiar examples. In all these the nut is surrounded by 
a kind of involucre, called a Cupule or Cup, which, however, is no 
part of the fruit. In the Oak, the cupule is a scaly cup ; in the 
Beech and Chestnut, it is a kind of bur ; in the Hazel, it is a leaf-like 
cup or covering ; in Hop-Hornbeam, it is a thin and closed bag. 
The fruit of the Walnut, Butternut, and the like, is between a drupe 
and a nut, having a fleshy outer layer. 
232. A Key or Key-Fruit (called by botanists a Samara) is like an akene or nut, 
or any other indehiscent, one-seeded fruit, only it is winged. The 
fruits of the Ash (Fig. 206) and of the Elm (Fig. 207) are of this 
kind. That of the Maple consists of two keys partly joined at the base, 
both from one flower (Fig. 208). 
233. Dehiscent Fruits, or dry fruits which split or burst open in some 
regular way, take the general name of 
234. Pods. These generally split lengthwise when ripe and dry. 
Pods formed of a simple pistil mostly open down 
their inner edge, namely, that 
which answers to the united mar- 
gins of the pistil-leaf. Compare 
Fig. 160 with Fig. 209 : the latter 
is the simple pod of a Marsh- 
Marigold open after ripening, and 
the seeds fallen, so becoming a 
leaf again, as it were. Some such 
pods also split down the back as 299 
well as down the inner side ; that 0pened p °" lcle - 
is, along what answers to the midrib of the leaf; as do pea-pods (Fig. 211). 
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