I20 UNIVERSITY OF MISSOURI STUDIES [26r 



connecting closely with the next two. 

 Quebec to Minnesota; Florida to Texas. 



280. 0. sulcata (Willd.) Nutt. [H. sulcata (Willd.) Britton^ 

 H. lacimosa (Michx. f.) Sarg.]. Big shell-bark hick- 

 ory. 



Rich ravines; scarce. 



New York to Michigan and Iowa; Pennsylvania to Ten- 

 nessee, Texas and Indian Territory. 



281. O. tomentosa (Lam.) Nutt. \H. alba (L.) Britton]. 

 Mocker-nut. 



Common on hillsides; variable, a frequent form having^ 

 five to seven leaflets and villous twigs. 

 Massachusetts to Michigan, Nebraska and Missouri. 



282. O. porcina Nutt. \H. glabra (Mill.) Britton]. Pig- 

 nut HICKORY. 



Rich hillsides; infrequent. 



Maine to Minnesota; Florida to Texas. 



283. O. amara Nutt. [/r.^^Vwrn^ (Marsh.) Britton]. Bit- 

 ternut. 



Along streams and in low grounds; occasional on rich 

 hillsides, or even dry ledges. 



Quebec to Minnesota; Florida to Texas. 



284. O. Olivaeformis Nutt. {^H. Pecan (Marsh.) Britton].. 

 Pecan. 



There is a grove of these trees near Rocheport, the origin. 

 of which is not definitely known. 

 Kentucky and Indiana to Iowa and Texas. 



Order 13. SALICALES. 



Family 23. SALICACEAE Lindl. Willow family. 



105. POPULUS L. Poplar. 



285. P. alba L. Abele. 



Frequently spontaneous in yards and roadsides. 

 Europe and Asia, thence to North America. 



