482 BOTANY. 



thick-shelled and stronger-tasting nuts are occasionally found in the 

 markets. 



J. cinerea, the White Walnut or Butternut, of the Eastern United 

 States, is a smaller tree, furnishing a valuable lighter colored timber 

 than the preceding. 



Two small species occur in California, Arizona, and Texas. 



Carya aba, the Shell-bark Hickory, and C. sulcata, both large trees, 

 of the Eastern United States, furnish a white, tough, and hard timber, 

 useful in the manufacture of agricultural implements, and for many 

 other purposes where great strength is required. It is not well adapted 

 to use in large masses, as it is liable to early destruction through decay 

 and the ravages of wood-boring insects. The fruits, known as 

 "Hickory-nuts," and highly prized for eating, are found incur mar- 

 kets, and are also exported to England. 



G. olivceformis, a small tree of the Southern States, furnishes a thin- 

 shelled edible fruit known as the "Pecan-nut." 



Other species of Carya furnish valuable timber, and from the nuts 

 of this and the preceding species valuable "nut-oils" used in paint- 

 ing are obtained. 



571. Cohort III. Asarales. Herbs, with mostly mon- 

 oclinous flowers, inferior ovary, and seeds with integuments, 

 containing minute embryo usually surrounded with endos- 

 perm. 



Order Rafflesiaceee. Parasites upon the stems and roots of Dicoty- 

 ledons. Twenty or more species are known, distributed throughout 

 the hotter parts of the world. 



Rafflesia Arnuldi, of Sumatra, is the most remarkable member of the 

 order. It consists of a gigantic parasitic flower nearly a metre in di- 

 ameter (3 ft.), with five mottled-red spreading petals. It is parasitic 

 upon a woody climbing plant (Cisms aiigustifolia) nearly related to the 

 Vine, and in its growth forms scarcely any stem, developing almost at 

 once into a giant flower-bud. It was discovered in 1818 by Dr. Arnold. 



Order Aristolochiaceee. Mostly tropical herbs, including about 

 200 species. Three species of Asarum, and three of Aristolochia occur 

 in the United States. 



572. Cohort IV. Nepenthales. Climbing shrubs, with 

 diclinous flowers, a superior three to four-cerled ovary, whose 

 many seeds contain an endosperm. 



Order Nepenthacese. Plants of the East Indies and Australia, of 

 ten or twelve species, all belonging to the genus Nepenthes. The 

 leaves are prolonged into a slender tendril-like organ, upon whose ex- 

 tremity there develops a hollow closed body, which finally becomes 

 open by the separation of its apex in such a manner as to form a 

 hinged lid (Fig. 383, d, e,f). In the cavities of these pitchers, as they 



