MS^ 



WALNUT FAMILY 



JUGLANDACE^ Lindley 



[|BOUT 6 genera compose this family, including some 35 species of 

 trees or shrubs mostly of the warmer portions of the north temperate 

 zone; they are of much economic importance, as the fruit of the ma- 

 jority of them contains a large nutritious, oily seed used for food and 

 from which a fixed oil is also expressed and used as food and for mechanical pur- 

 poses. The bark and husks of some of the walnuts are used as dyestuffs and in 

 medicine as astringents and cathartics; their wood is much esteemed for cabinet 

 work. The fruits of the hickories are also much used for food and their wood is 

 valued on account of its strength and flexibility. Many fossils referable to this 

 family have been found in North America, over 30 species of fossil Juglans and 

 about 10 of Hicoria having been described. 



The Juglandaceae have alternate, pinnately compound leaves, without stipules. 

 The flowers are monoecious; the staminate are borne in lateral, long drooping 

 catkins and consist of an irregular, 2- to 6-lobed perianth, which is sometimes 

 united to a bract or may be entirely wanting; stamens 3 to many in several series, 

 inserted upon the perianth, if present; their filaments are distinct; anthers erect, 

 2-celled, opening lengthwise; rarely a rudimentary ovary is present. The pistil- 

 late flowers are terminal, soUtary or in clusters, and consist of an incompletely 

 2- to 4-celled ovary, subtended by an involucre of more or less united bracts and 

 2 lateral bractlets; style terminal, short; stigmas 2, long, stigmatic on the inner 

 side or sometimes plumose ; ovules sohtary. Fruit in the North American genera 

 drupe-hke, the dry, hard, or fibrous husk dehiscent or inidehiscent, enclosing a 

 crustaceous or bony, smooth, or sculptured nut; the seed is large, oily, 2- to 4-lobed 

 with a papery coat; endosperm none; embryo large; cotyledons fleshy and wrinkled. 



Husk indehiscent; nut sculptured; staminate catkins solitary, thick, sessile or but 



short-stalked. 1. Juglans. 



Husk splitting into several segments; nut not sculptured; staminate catkins in 3's, 

 slender, long-stalked. 2. Hicoria. 



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