Trees of the Northern United States 139 



without a hand lens; annual rings distinct by 

 a fine line of denser late wood cells, often 

 quite indistinct; pores scattered tliru the an- 

 nual ring; no zone or no very definite ring 

 of collected pores in the early wood. Magnolia, 

 Liriodendron, Persea, , Tilia, Sorbus, Pyrus, 

 Malus, Cydonia, Amelanchier, Crataegus, 

 Prunus, Amygdalus, Euonymus, Ilex, Staphy- 

 lea, Aesculus, Acer, Hamamelis, Liquidambar, 

 Platanus, Fagus, Carpinus, Ostrya, Betula, 

 Alnus, Juglans, Myrica, Populus, Salix, Rho- 

 dodendron, Kalmia, Oxydendrum, Symplocos, 

 Halesia, Forestiera, Cornus, Cynoxylon, Nyssa, 

 Cephalanthus, Viburnum. 



a. Amiong the above, those having liiit,!/!^ 

 colored or dark heartwood are the follow- 

 ing: Persea, Prunus, Amygdalus, Liqui 

 dambar, Fagus, Juglans, Oxydendrum. 

 Halesia. 



Wood ring-porous, the pores or wood vessels 

 numerous and usually visible in cross section 

 without a hand lens; annual rings distinct by 

 a zone or ring of large pores in the early 

 wood alternating with a denser zone of late 

 wood containing fewer or smaller pores. 

 Asimina, Sassafras, Zanthoxylum, Ptelea, Ail- 

 anthus, Cercis, Gleditsia, Gymnocladus, Clad- 

 rastis, Robinia, Rhamnus, Sapindus, Koelreu- 

 teria, Rhus, Toxicodendron, Cotinus, Ulmus, 

 Planera, Celtis, Morus, Toxylon, Papyrius, 

 Castanea, Quercus, Hicoria, Bumelia, Dios- 

 pyros, Chionanthus, Fraxinus, Paulownia, 

 Catalpa, Aralia. 



a. Among the above, those having highly col- 

 ored or dark heartwood are the following: 

 Asimina, Cercis, Gleditsia, Gymnocladus, 

 Robinia. Rhus, Toxicodendron, Cotinus. 

 Morus, Toxylon, some species of Quercus. 

 Hicoria, Diospyros, Catalpa, Aralia. 



