TAXODIUM 2 1 7 



wood chiefly rectangular, rather uniform, and somewhat thick-walled. 

 Resin cells very numerous, the resin chiefly in a peripheral layer ; 

 scattering throughout the growth ring or occasionally becoming more 

 or less zonate. Medullary rays prominent, numerous, and i cell wide, 

 distant 2-9 rows of tracheids. 



Radial. Medullary rays conspicuously resinous, numerous ; the cells not 

 much contracted at the ends, equal to about 6 tracheids. The upper 

 and lower walls thickish, unequal, irregularly and often distantly 

 pitted, the pits rather broad ; the terminal walls thin, not pitted or 

 locally thickened, chiefly strongly curved ; the lateral walls with small, 

 rather obscure, oval pits, 1-2 per tracheid, the orifice narrowly lenticu- 

 lar, often slitlike. Resin cells very numerous, upwards of 20 p. wide and 

 200 p. long. Bordered pits small, round, distant in i row. Pits on the 

 tangential walls of the summer wood numerous, conspicuous, open. 



Tangential. The I -seriate rays very numerous, medium ; the oval or round 

 cells somewhat thick-walled, rarely in pairs. 



6. * TAXODIUM, RICH. PLATES 30 AND 31 



Transverse. The summer wood of the usually broad growth rings much 

 less than the spring wood. Resin passages wholly wanting. Resin 

 cells numerous and prominent, either scattering or zonate. 



Radial. Rays wholly without tracheids, the cells commonly contracted at 

 the ends. Tracheids wholly without spirals. 



Tangential. Fusiform rays wholly wanting, the cells of the i-seriate rays 

 broadly oval. 



SYNOPSIS OF SPECIES 



Resin cells large, numerous, more or less distinctly zonate. 



Pits on the lateral walls of the rays cells 1-4, more rarely 7, per tra- 

 cheid, the lenticular orifice narrow. 



Bordered pits numerous, often paired, or in the earlier spring 

 wood imperfectly 2-rowed. 



1. * T. distichum. 



Resin cells obscure and forming an open zone on the inner face of the 

 summer wood. 



Pits on the lateral walls of the ray cells about 2-3 per tracheid in 

 radial series. 



Bordered pits numerous, in the earlier spring wood crowded into 2-3 

 compact rows, but becoming 2-rowed toward the summer wood. 



2. * * T. laramianum. 



1. * T. distichum, Rich. 



Bald Cypress. Deciduous Cypress 



Transverse. Growth rings usually very broad. The dense and conspicu- 

 ous summer wood often double or treble ; transition to the spring 



