'THE FRUIT. 203 



invested by the swollen and succulent fruit-like calyx. The 

 fruits of tne dandelion, sun-flower, and all Compositse, are 

 achenia or single-seeded pericarps. Each has been produced 

 by a separate flower, and is provided with a persistent calyx 

 the tube of which is closely united to the fruit, its limb form- 

 ing a beautiful stellate down at the summit of the style or 

 ovary, by means of which the achenium or mature ovary is 

 lifted from off the surface of the broad and dilated receptacle 

 and wafted by the winds to spots favorable to its germination. 

 The bottom of the persistent calyces of the Labiatae or mint 

 family usually contain four achenia which look at first like 

 seeds, and were actually regarded by Linnaeus as such. He 

 defines them as "semen tectum epidermide ossea," that is 

 seed covered with an osseous epidermis, and hence he called 

 the whole order gymnospermia, (yvpvo$ naked, <jrtfp^ta a seed.) 

 The student may however easily satisfy himself that such is 

 not the case, and ascertain that they are pericarps or seed 

 vessels by cutting across them, when he will discover the true 

 seed in their interior. 



The Cremocarp. This fruit is confined to the great 

 natural order Umbelliferse, of which the carrot and parsley 

 are familiar examples. The Cremocarp (xpcftcuo, to suspend,) 

 is composed of two achenia, which are at first united to a 

 common axis called the carpophore, (xaprto?, fruit, and $op, I 

 bear,) which axis separates at maturity, as in Fig. 100, the 

 two achenia being placed apart and suspended from its summit. 

 Each of these achenia is called a mericarp (n*epo$, part,) or 

 hemicarp, (q/uav?, half, and xaprtbs, fruit.) 



The Samara, (samera, seed of elm.) This is an achenium 

 with a membranaceous appendage attached to its summit or 

 margin, and forms those peculiar winged fruits suspended in 



