160 



FAMILIES OF FLOWERING PLANTS 



mens are 4-12; and the 2-lobed ovary becomes in fruit a familiar "key" 

 or samara, differing greatly in sliajDe. Maple wood is hard, of variable 

 density and color; it is ordinarily susceptible of a fine polish, and plays 

 an important part in cabinet making. 



Family Hippocastanaceae. Horse-chestnut Family. Contains two 

 genera, JEscidus, with about 15 species, and BilUa, Avitli 2, the latter 

 Mexican. They are trees or shrubs with palmately di\dded leaves and 

 perfect, irregular flowers borne in large pyramidal panicles. The calyx 

 is bell-shaped; petals 4 or 5, long-clawed; stamens 5-8; ovary 3-celled, 

 becoming a leathery capsule containing 1-3 large shining seeds. 



The common horse-chestnut (^. Hippocastanum) of our streets and 



parks is a native of Asia, but 

 has escaped from cultivation 

 in man}- places in the East. 

 The western buckej^e {jE. 

 glabra) is well shown in the 

 accompanying photograph 

 (Fig. 140.) There are sev- 

 eral other ornamental native 

 species, some with red and 

 some with yellow flowers. 



Family Sapindaceae. 

 Soapberry Family. Con- 

 tains about 120 genera and 

 over 1000 species, of wide 

 distribution in tropical and 

 semitropical regions. They 

 are trees or shrubs with 

 mostly pinnate or palmate 

 leaves, and regular or irreg- 

 ular, perfect or sometimes dioecious flowers. Calyx 4-5 lobed or di- 

 vided; petals 3-5, borne on a fleshy disk, as are the 5-10 stamens; fruit 

 a berry or a capsule, the latter sometimes bladdery -inflated, as in the 

 balloon vine {Gardiosj^ermum) of our gardens. 



Sapindus is a genus of about 10 species, one or two of which are 

 found within our borders. They are called soapberries, from the fact 

 that the outer covering of the fniit contains a saponaceous principle 

 used extensively in the tropics in place of ordinary soap. The hard 

 round seeds of some species are used for making necklaces and rosa- 

 ries. Serjania and Paidlinia are two very large genera of climbing 

 shrubs, common in tropical regions. The seeds of P. sorb His, the gua- 

 rana, are made into compressed cakes from which a cooling beverage is 

 prepared, and form an extensive article of trade in Brazil. Litchi nuts, 



EM.7^ 



Fig. 13S. The bladder-nut {Staphylea trifolia) show- 

 ing flowering branch and detached fruit. Original. 



