136 



ORGANOGRAPHY. 



rum perfoUatuvi) and Yellow-wort (Chlora perfoliata), it is per- 

 foliate, because the stem appears to pass through the leaf; or 



Fig. 259. 



Fig. 261. 



Fig. 262. 



Fig.2o9. Shent'iing leaf of a Grass Fir;. 260. Decurrent leaf of a spe- 

 cies of Thistle. Fifj. '2(>i. Perfoliate leaf of a species of Ilare's-ear 



(Ruphitniiii rotmidifolium.) Fir/. 2(j2. Connate leaves of a species of 



Honeysuckle {Lonicera Caprifolium). 



when two leaves placed on opposite sides of the stem unite by 

 their bases they are said to be connate (fg. 262), as in the 

 Teasels (DIpsacus fullonmn and .^iflvestris), and some species 

 of Honeysuckle {Lonicera Caprifolium'), &c. 



2. The Arrangement of Leaves on the Stem or Phyl- 

 LOTAXY. — When only one leaf arises from a node, the leaves as 

 they succeed each other are placed alternately on different sides 

 of the stem, in which case they arc said to be alternate {fig. 266). 

 This arraiifrcmeut occurs in nearly all Monocotyledouous Plants, 

 and in the larger number of Dicotyledonous Plants also after 

 the first two or three nodes are developed. When two leaves 

 arc produced at a node, they arc usually placed on opposite sides 

 of tlic stem, in which case they are said to be opposite (fig. 264); 

 or when three or more leaves arise from the stem so as to be 

 arranged around it in the form of a circle, they are said to be 

 verticillate or whorled (fig. 263), and each circle is termed a 



