CARYA 65 



c. Terminal bud covered with silvery 



scales 8. C. pallida 



1. _C. illinoensis (Wang. ) K. Koch.Pecan. (C. pecan (Marsh. ) 

 Engl, and Graebn. ). Tree up to 50 m. high, and with a trunk diam- 

 eter of 6-12 dm., buttressed at the base; bark very thick, fur- 

 rowed, ridged; buds flattened, with paired valvate narrow scales 

 covered with jointed hairs; fruit elongate, the ripe husk splitting 



to below the middle; nut reddish-brown, elongate, subcylindric, 

 ellipsoid or ovoid; shell thin; kernel sweet. Bottomlands, Indiana 

 to Iowa, south to Alabama and Texas. 



2. C. cordiformis (Wang. )K. Koch. Bitternut Hickory. A 

 slender tree 15-50 m. high, the trunk 3-7. 5 dm. in diameter ;bark 

 close and rough; bud-scales valvate in pairs, bright yellow; husk 

 of fruit thin, splitting slowly into 4 valves; nut globular, thin-wall- 

 ed; seed extremely bitter. Woods, Florida to Texas, north to New 

 Hampshire, Minnesota, and Nebraska (Fig. 43). 



3. C. ovata (Mill. ) K. Koch. Shagbark Hickory . A handsome 

 tree 20-28 m. high, the trunk 3-6 dm. in diameter; bark shaggy, 

 exfoliating in rough strips; twigs gray or brown, puberulent or 

 glabrate; bud scales several, imbricated; fruit-husk thick, split- 

 ting quickly into four valves when mature; nut flattish- globular, 

 thin-walled; seed sweet. Rich woods and slopes, Florida to Texas, 

 north to Maine, Minnesota, and Nebraska (Fig. 44). 



4. C. laciniosa (Michx,f. ) Loud. Shellbark Hickory . A tree . 

 20-40 m. high, the trunk 3-6 dm. in diameter; bark separating 

 into long narrow straight plates; twigs buff or orange; fruit-husk 

 thick, splitting quickly into four valves when mature; nut large, 

 3-5 cm. long, angular, thick-walled; seed sweet. Bottomlands, 

 New York to Iowa and Nebraska, south to Alabama and Louisiana 

 (Fig. 45). 



5. C. tomentosa Nutt. Mockernut. White Hickory. (C. alba 

 K. Koch). A tree 20-40 m. high, the trunk 3-7.5 dm. in diameter; 

 bark close, rough, but not shaggy or exfoliating; twigs tomentose- 

 pubescent; outer bud-scales falling early, giving the bud a clean 

 neat silvery appearance; fruit-husk thick and hard, splitting to the 

 base; nut globular, quite thick-shelled (hence the common name, 

 mockernut); seed sweet. Woodlands, Florida to Texas, north to 

 Vermont, Michigan, and Nebraska (Fig. 46), 



6. jC. glabra (Mill. ) Sweet Pignut Hickory. A tree 20-30 m. 

 high, the trunk 3-10 dm. in diameter; bark close, rough; twigs 

 glabrous or nearly so; terminal bud small, less than 10 mm. long; 



