IV. 2. THE PIGNUT HICKORY. 197 



attains a considerable size only when growing on a rich soil. 

 In this State, it flourishes in company with the shellbark, and 

 prevails in the eastern parts, particularly in the vicinity of 

 Boston, and more on the southern side than on the northern or 

 eastern. 



Sp. 3. The Pignut Hickory. Carya porcina. F. A. Michaux. 

 Figured in Michaux, Sylva, Plate 38 ; and on Plate 14 of this volume. 



Although the pignut hickory occurs more frecmently than 

 any other species, yet the name is often made to include the 

 mockernut and the bitternut. 



The bark of the pignut hickory is broken into finer and more 

 numerous rugosities than either of the preceding species, and 

 begins to assume its roughness at an earlier age, and on smaller 

 trunks and branches. Its color is a rather light bluish, ashen 

 gray, and it is often clouded with large patches of gray and 

 sulphur-colored, or bluish lichens. On old trunks, the bark is 

 comparatively smooth, but sometimes broken into larger and 

 less regular plates than the mockernut, and the plates are rough 

 and often projecting, somewhat as on the shellbark. 



The recent shoots are smaller than those of the two preceding 

 species, tapering, smooth, often polished, purple, with numerous 

 long dots, and gradually turning brownish gray ; the larger 

 branches are of a uniform bluish gray. The leaves are long, 

 with three, five, or seven leaflets, on a long, smooth footstalk. 

 The leaflets are nearly sessile, narrower than in the former 

 species, smooth on both surfaces, tapering gradually at both 

 extremities, and ending in a long point. The terminal leaflet is 

 inversely egg-shaped, on a short stalk. When crushed, the 

 leaves, as well as the husk of the nuts, give a not unpleasant 

 odor, entirely different from the characteristic odor of the 

 mockernut hickory. In autumn, as early as October, the leaves 

 change their color, becoming of a russet orange, or often a rich 

 orange with a brown tint overspread. 



The buds are egg-shaped and pointed, or rounded, smaller 

 than in the last species, the outer scales of a polished brown. 



The fruit of the pignut hickory varies still more in shape 



