260 INDEHISCENT APOCARPOUS FRUITS. 



allowing the seeds ultimately to escape, as is common in fleshy fruits, 

 or remaining united to the seed, and being ruptured irregularly when 

 the young plant begins to grow ; such fruits are indehiscent. Other 

 apocarpous fruits, when mature, open spontaneously to discharge the 

 seeds, and are dehiscent. 



540. indehiscent Apocarpous Fruits, when formed of a single mature 

 carpel, frequently contain only one seed, or are monospermous (1*61*0$, 

 one, and ani^a,, seed). In some instances there may have been only 

 one ovule originally, in others two, one of which has become abortive. 



541. The Achcenium (, privative, and -^a-ivu, I open) is a dry 

 monospermous fruit, the pericarp of which is closely applied to the 



seed, but separable from it (fig. 

 463). It may be solitary, form- 

 ing a single fruit, as in the 

 Cashew (fig. 227 a), where it 

 is supported on a fleshy pedun- 

 cle, p; or aggregate, as in 

 Ranunculus (fig. 464), where 

 several achasnia are placed on 



~fr;3* 464 a common elevated receptacle. 



In the Strawberry, the achtenia 



are placed on a convex succulent receptacle. In the Eose, they are 

 supported on a concave receptacle, covered by the calycine tube (fig. 

 270), and in the Fig, they are placed inside the hollow peduncle or 

 receptacle (fig. 246), which ultimately forms what is commonly caEed 

 the fruit. In the Eose, the aggregate achsenia, with their general 

 covering, are sometimes collectively called Cynarrhodum (KVUV, a dog, 

 and go'Soi/, a rose, seen in the dog-rose). It will thus be remarked, 

 that what in common language are called the seeds of the Strawberry, 

 Eose, and Fig, are in reality carpels, which are distinguished from 

 seeds by the presence of styles and stigmas. The styles occasionally 

 remain attached to the achaania, in the form of feathery appendages, 

 as in Clematis, where they are called caudate (cauda, a tail). 



542. In Composite, the fruit which is sometimes called Cypsela 

 (KV^&D, a box), when ripe, is an achasnium united with the tube of 

 the calyx (fig. 279 t). The limb of the calyx hi the Compositas, some- 

 times becomes pappose, and remains attached to the fruit, as in 

 Dandelion, Thistles, &c. (fig. 279 t). When the pericarp is thin, 

 and appears like a bladder surrounding the seed, the achasnium be- 

 comes a Utricle, as in Amaranthacea3. This name is often given to fruits 

 which differ from the achsenium, in being composed of more than one 



Fig. 463. Achaenium or indehiscent monospermous carpel from the pistil of a Ranunculus. 



Fig. 464. 1. Similar achsenium, with rough points on the pericarp, from the pistil of Ranun- 

 culus muricatus. 2. Achsenium cut transversely to show the seed, g, not adherent to the 

 parietes. 



