28 Introduction to Botany. 



globose or ovoid ; husk fibrous and indehiscent ; the shell or endocarp 

 rugose or sculptured. 



1. Juglans cinerea, L. (L., cinereus, ash-colored.) BUTTERNUT or White 

 Walnut. Trees, usually of moderate size and rather smooth gray bark; young 

 shoots, etc., viscid-pubescent. Oblong lanceolate leaflets 11-19, downy beneath. 

 Drupes oblong and pointed and clammy. Rich woods. 



2. Juglans nigra, L. (L., niger, black.) Black Walnut. Becoming large 

 trees with rough bark; petioles and young shoots puberulent, becoming glabrous 

 when older. Ovate-lanceolate leaflets 13-23. Fruit globose, not viscid. Rich 

 woods. 



n. CARYA. Hickory. 



(From Gr., karya, the walnut.) 



Staminate flowers of 3-10 stamens in clustered lateral aments ; pis- 

 tillate flowers in clusters of 2-5 on a terminal peduncle. Calyx 4- 

 toothed, petals wanting. Drupes subglobose, oblong, or ovoid ; husk 

 separating into 4 valves ; nut bony, sniooth, or angled. 



1. Carya alba, Nutt. (L., albus, white.) Shellbark or Shagbark 

 Hickory. Old bark falling off in broad strips. Leaflets 5, or rarely 7, the 3 

 upper lance-obovate and much larger than the lower. Opening terminal buds 

 very conspicuous, the bracts enlarging and persisting until the flowers are fully 

 developed. Staminate flowers on slender peduncles at the bases of shoots of the 

 current season. Nut somewhat compressed and angled, and slightly mucronate 

 at the apex. Shell rather thin. Husk splitting into 4 valves. Seed sweet. In 

 rich soil. 



2. Carya sulcata, Nutt. (L., sulcatus, furrowed.) Big Shellbark. Bark 

 separating in long strips. Leaflets usually 7-9, downy beneath. Nut from ij to 

 2 inches long, usually angular and prominently pointed at both ends. Seed sweet. 

 Husk and shell thick. Bottom lands and moist woods. 



3. Carya porcina, Nutt. (L., porcinus, pertaining to a hog.) PIGNUT. Some- 

 times becoming large trees; bark rough; foliage usually smooth, sometimes 

 pubescent; leaflets 3-7, infrequently 9, oblong-lanceolate or obovate-lanceolate, 

 acuminate, 3 to 6 inches long. Fruit obovoid or obovoid-oblong. Husk ihin, incom- 

 pletely or tardily dehiscent. Nut thin-shelled, angled, and pointed. Seed bitter. 

 Uplands. 



4. Carya olivEeformis, Nutt. (L., oliva, olive; forma, form.) Pecannut. 

 Becoming tall trees with rough bark. Shoots pubescent while young, but becom- 

 ing glabrous with age. Leaflets 11-15, short-petioled, oblong-lanceolate, and some- 

 what falcate toward the apex. Staminate aments fascicled near the apex of the 

 previous year's growth. Fruit from i^ to q\ inches long, oblong-cylindrical; husk 

 thin; nut thin-shelled and smooth; seed sweet. In moist soil and along streams. 



