[PBNHALLOW] N. AMERICAN TAXACEvE AND CONIFERiE SI 



3. JUNIPERUS, L. 



Transverse. Growth-rings generally narrow, often unconformable and 

 coalescent on the narrow side. Summer wood very thin but dense. 

 Eesin- passages wholly wanting. Eesin-cells rather numerous, pro- 

 minent, and chiefly in tangential bands, often giving rise to the 

 appearance of secondary growth-rings. 



Radial. Eays chiefly without tracheids, very numerous, often very resin- 

 ous. Ray-cells chiefly straight, the terminal walls thin and entire, 

 more rarely somewhat pitted, the pits on the lateral walls often with 

 a more or less obvious border. Tracheids wholly without spirals. 



Tangential. Fusiform rays wholly wanting. Ordinary rays one to two- 

 seriate, the cells oval, chiefly broad. 



Species. 



1. J. californica, Carr. J. occidentalis, var. conjugens, Engel. 



" " Yvir. utahensis, CdiYT. " " var. 7Jio?ios?3ermci, Engel. 



2. J. pachyj^hlœa, Torr. .5. .7. communis, L. 



3. J. vlrginiana, L. 6. J. sabina, L. 



4. J. occidentalis, Hook. " " var. procumhens, Pursh. 



4. LiBocEDRus, Endl. 



Transverse. Summer wood thin, rather dense, usually showing a median 

 layer of denser structure. Resin-passages wholly wanting. Resin- 

 cells numerous and in conspicuous tangential bands. 



Radial. Rays without tracheids. The terminal walls of the ray-cells 

 straight or somewhat curved, entire, locally thickened, or even some- 

 what coarsely pitted ; the lateral walls with small and simple pits 

 Tracheids wholly without spii-als. 



Tangential. Rays of one kind only. 



Species. 

 1. L. deciirrens, Torr. 



5. Taxodium, Rich. 



Transverse. Growth-rings rather broad, the summer wood about one 

 third the spring wood. Resin-passages none. Resin-cells numer- 

 ous, prominent and scattering or in tangential bands. 



Radial. Rays without tracheids. Ra^^-cells more or less conspicuously 

 contracted at the ends ; the lateral walls with conspicuously bor- 

 dered pits, the orifice narrow. Tracheids wholly without spirals. 



Tangential. Fusiform rays none. Ordinary rays one-seriate, the cells 

 broadly oval. 



Species. 

 1. T. distichiim, Rich. 



