4 6 



Commercial Gardening 



nut (fig. 35), and Aralia Veitchi. The latter three have palmate leaves. 

 The feathered type of compound leaves is termed unequally pinnate in 



the Rose, Robinia (tig. 36), Ash, Elder, and 

 Walnut. The Laburnum and Clover have 

 ternate leaves, because cut up into three 

 jointed leaflets. The forms of leaves are prac- 

 tically endless, and should be studied from the 

 textbooks. 



The surface of leaves may be smooth or 

 glabrous, that is, without hairs, or they may 

 be covered with hairs varying greatly in den- 

 sity, length, or form. Hairs that lie smooth 

 and close are silky; those that are interwoven 

 with one another are felted or tomentose (fig. 

 37); long and loose ones may make the leaves 

 shaggy or woolly. Amongst the hairs on the 

 leaves of the Nettle some have a swollen base 

 and are stinging. Those of the Stock are 

 branched in a starry fashion and are termed 

 stellate. To this class belong the hairs on 

 Draba (fig. 37), while this is carried further 

 in Elseagnus and other shrubs, the branches 

 of the hairs being united in the form of cir- 

 cular scales, like a Japanese parasol in mini- 

 ature, with a very short stalk. The hairs are 

 useful in a variety of ways, by running the 

 moisture off the plants, by preserving the 

 liquids in the leaves of plants that live in dry places; while the hairs and 

 bristles on many Cacti serve to keep them cool 



under the influence of 



a scorching sun in 



desert regions. 



Arrangement of 



Leaves. They are op- 

 posite or in pairs in the 



Carnation and Sweet 



William; in whorls of 



three in the Oleander, 



and in whorls of four, 



six, eight, or a higher 



number in species of 



Bedstraw. They are 



alternate in the Lime, 



Beech, Elm, and others, 



where the third leaf comes in a line with the first, counting upwards or 

 downwards. They are spirally arranged on the shoots. This also applies 



Fig. 34. Seedling with opposite Coty- 

 ledons and alternate Foliage Leaves 

 (Cytisus Laburnum) 



Fig. 35. Horse-chestnut -Com- 

 pound Palmate Leaf 



. 36. Robinia Compound 

 Unequally Pinnate Leaf 



