1844 A TEXTBOOK OF THEORETICAL BOTANY 



ryales on the one hand and with the Fagales on the other. Hutchinson 

 considers that these famihes may represent reduced forms which originated 

 from the Rosales through the Hamamehdaceae. While the question is a 

 very obscure one and outside the scope of this book we have referred briefly 

 to the Myricales under the SaHcales (see p. 1756). Hence in this treatment 

 the Juglandales will be regarded as possessing only a single family Jug- 

 landaceae. 



In the Juglandaceae the flowers are monoecious. The male inflores- 

 cence consists of a many-flowered catkin, each flower being borne in the 



Fig. 1747. — jfiiglans regia. 

 flowers. 



axil of a bract and composed of a perianth of scale leaves and from three to 

 forty stamens. In the female flower (Fig. 1747) the bract and bracteoles 

 are fused to the inferior ovary, as are also some four rudimentary perianth 

 leaves. The ovary consists of two carpels with a pair of large stigmas. The 

 fruit is a nut or drupe with a thin epicarp and fleshy mesocarp ; the endocarp 

 is hard and may give rise to either two or four incomplete septa. 



There are six genera and about forty species in the family. They are 

 trees usually with large compound leaves and are found in the warmer 

 parts of the north temperate regions. There is evidence that in 

 Cretaceous times the family extended as far north as Greenland. 



The most important members are the Walnuts; Jiiglam regia is the 

 Common Walnut while J. nigra is the Black Walnut. Species of the genus 

 Carya provide the Hickory or Pecan nuts of commerce. 



UMBELLIFLORAE 



The Umbelliflorae are Archichlamydeae in which the flowers are 

 hermaphrodite, polypetalous and epigynous. They are tetramerous or 

 pentamerous, with one series of stamens, and the gynoecium is inferior, 



