>(> .NOMENCLATURE OF THE LEAF. 



m. Emerging when the leaf is raised upon its foot-stalk above 

 the surface of the water, as in the greater water plantain. 



n. Floating resting on the surface of the water, as in broad- 

 leaved pond-weed and white-flowered water-lily. 



o. Sunk submersed or immersed, entirely under water, as with 

 marsh water-violet and perfoliate pond-weed. 



11. Distribution: The words, opposite, decussated, 

 ternate, cruciate, whorled, alternate, spiral, scattered, 

 two-ranked, tufted, crowded, imbricated, rose-like, 

 crowning, and remote, are employed to denote the dis- 

 tribution of leaves on the stem and branches. 



a. Opposite when they appear directly on opposite sides of the 

 stem in pairs, as in white archangel and common nettle. (F. 48.) 



b. Decussated crossing each other in pairs cross-like, as in 

 caper spurge and four-sided crassula. (F. 54.) 



c. Ternate when the leaves stand by threes round the stem, as 

 in verbena tryphylla. 



d. Quaternal when in fours, as in various species of heath. 



e. Cruciate or cruciform when in four leaves lying on the sur- 

 face of the horizon, each leaf pointing to an opposite direction. 

 (F. 48.) 



f. Whorled or verticillated when the number ofleaves surround- 

 ing the stem or branch exceeds four, and point to different directions, 

 forming a star-like figure. (F. 55.) 



g. Alternate when not in pairs, and are given off in various 

 directions one after another, as in round-leaved mallow. (F. 71.) 



h. Spiral alternate, forming a spiral line around the common 

 axis, as in the Norway spruce fir. 



i. Scattered alternate and irregularly placed. 



J. Two-ranked alternate, spreading in two directions, and yet are 

 not regularly opposite at their insertion, as in the yew-tree, decidu- 

 ous cypress and silver pine. 



k. Tufted or fasciculated when several leaves spring from the 

 same point, as in common larch and common berberry. The terms 

 " bina, terna," &c. are ased to express two, three, or the number of 

 leaves which enter into each tuft. 



1. Crowded clustered together, as in chick-weed winter green. 



