54 
HOW PLANTS GROW. 
152. Stipules, as already explained (120), are a pair of appendages at the base ot 
the leaf, one on each side. These often grow fast to the base of the leafstalk, 
as they do in the Rose and in Clover (Fig. 136; sf 3 
the stipules). Or they may join with each other and 
form a kind of sheath round the stem, as they do in 
the Buttonwood and in Polygonum (Fig. 137). 
Many leaves have no stipules at all. In many 
cases they fall olf very early, especially those that 
serve for bud-scales, as in Magnolia. 
153. The Arrangement of Leaves on the stem has 
already been explained as to the two principal ways 
(59). Leaves are either 
Alternate, when they follow each other one by one, 
as in the Morning-Glory (Fig. 4) and the Linden 
(Fig. 83) ; or 
Opposite, when in pairs, 
that is, two on each joint of 
stem, one opposite the other, 
as in Maples (Fig. 84). To 
these may be added a third, 
but less common arrangement, 
viz. the 
Whorled ; where there are 
three, four, or more leaves on 
the same joint of stem, forming 
a circle or whorl; as in Madder and Bedstraw (Fig. 137'). 
variety of the opposite mode. 
Whorled leaves. 
But this is only a 
Analysis of the Section. 
81. Vegetation very simple in plan, very diversified in particulars. 82. The study of the forms of 
the organs is Morphology. 
83-89. Roots, their forms and kinds. 84. Primary or original; secondary; how they originate. 
85. Aerial roots. 86. Aerial rootlets. 87. Air-Plants ; how they live. 88. Parasitic Plants, their 
economy. .89. Shapes of roots : fibrous; fleshy; the principal sorts. 
90. Forms or kinds of stem; herbaceous, shrubby, arboreous. 91. Culm or straw-stem. 92. Direc- 
tions or positions of stems. 93. Peculiar sorts. 94. Thorns or Spines, how she wn to be branches ; 
