CLASSIFICATION OF THE MONOCOTYLEDONS. 157 



pies are the various species of Tradescantia (Fig. 88), some 

 of which are native, others exotic. Of the cultivated forms 

 the commonest is one sometimes called " wander ing- jew," a 

 trailing plant with zigzag stems, and oval, pointed leaves 

 forming a sheath about each joint. Another common one is 

 the spiderwort already referred to. In this the leaves are long 

 and pointed, but also sheathing at the base. When the flowers 

 are showy, as in these, the sepals and petals are different, the 

 former being green. The flowers usually open but once, and 

 the petals shrivel up as the flower fades. There are four 

 families of the order, the spiderwort belonging to the highest 

 one, Commelynece. 



ORDER III. Spadicijiorce. 



The third order of the monocotyledons, Spaditiflorce, is a 

 very large one, and includes the largest and the smallest plants 

 of the whole sub-class. In all of them the flowers are small 

 and often very inconspicuous ; usually, though not always, 

 the male and female flowers are separate, and often on dif- 

 ferent plants. The smallest members of the group are little 

 aquatics, scarcely visible to the naked eye, and of extremely 

 simple structure, but nevertheless these little plants produce 

 true flowers. In marked contrast to these are the palms, some 

 of which reach a height of thirty metres or more. 



The flowers in most of the order are small and inconspicuous, 

 but aggregated on a spike (spadix) which may be of very large 

 size. Good types of the order are the various aroids (Aroidece)j 

 of which the calla (Richardia) is a very familiar cultivated 

 example. Of wild forms the sweet-flag (Acorus), Jack-in-the- 

 pulpit (Ariscema) (Fig. 86, A } Z>), skunk-cabbage (Symplocar- 

 pus)j and wild calla may be noted. In Ariscema (Fig. 86, A) 

 the flowers are borne only on the base of the spadix, and the 

 plant is dioecious. The flowers are of the simplest structure, 

 the female consisting of a single carpel, and the male of four 



