FAMILIES OF FLOWERING PLANTS 167 
may be distinguished very easily. 
They are climbing or erect shrubs 
with alternate leaves and watery 
juice. The small greenish flowers 
are either perfect or dioecious, and 
are borne in variously shaped 
clusters. The petals are 4-5, and 
fall soon after the flower expands. 
~When tendrils are present they 
are borne apparently opposite the 
upper leaves, the inflorescence 
being opposite the lower leaves as 
shown in Fig. 143. These ten- 
drils, however, are technically re- 
garded as abortive shoots. 
The Virginia creeper (Par- 
thenocissus quinquefolia) is another 
Fig. 146. Grewia orientalis showing flowering 
member of the family, as also the branch and enlarged flower. Original. 
Fig. 147. Flower of Hibiscus schizopetalus showing the 
monadelphous stamens. Drawn from aphotograph by Mr. 
G. N. Collins. 
Japanese ivy (P. tricuspidata). 
The very large genus Cissus 
is widely represented in trop- 
ical Asia. 
CHAPTER XXIV. 
Order Malvales. 
This very distinct order 
contains eight families, the 
most important being the 
Madvaceae or Mallow Family 
and the Tiliaceae or Linden 
Family. Like the preceding 
order they are distinguished 
mainly by floral characters. 
The sepals are called by 
botanists valvate, which 
means that in the bud before 
unfolding their edges just 
meet without overlapping, in 
which case they would have 
been imbricated. The valvate 
sepals may be easily observed 
in the flower of any common 
mallow. The ovule-bearing 
walls within the ovary are 
