86 



Qiiercus Rydbcrgiana Cockerell. The leaves are somewhat 

 more advanced than those of Q. grisea ; their color is always 

 pink. After considerable study, I think this plant is (like Q. grisea) 

 best regarded as a subspecies of Q. undiilata, namely Quercus 

 undulata Rydbergiana, notwithstanding differences in the leaves 

 and fruit. All things considered, I do not feel perfectly assured 

 that there is more than one valid species of the undulata group at 

 Las Vegas Hot Springs, but since five easily recognizable types 

 are undoubtedly present, it is proper that they should have names 



of some sort. 



East Las Vegas, N. M. 



A KEY TO THE NORTH AMERICAN SPECIES OF 



PANUS 



By F. S. Earle 



i. Stipe excentric ; pileus irregular. 

 Stipe lateral. 

 Stipe wanting ; pileus sessile or resupihate. 



2. Pileus squamulose, strigose or velutinous. 

 Pileus glabrous. 



3. Pileus white. 

 Pileus colored. 



4. Pileus infundibuliform, slightly velvety. 

 Pileus somewhat depressed, villous or strigose. 



5. Pileus 7-8 cm., villous, whitish. 

 Pileus 20 cm., strigose, whitish. 



6. Pileus cinnamon, becoming expellent, breaking into scales 

 Pileus alutaceous, densely floccose-appressed, scaly. 



7. Cespitose. 

 Not cespitose. 



8. Stipe tomentose. 

 Stipe glabrous. 



9. Lamellae free ; pileus brown. 

 Lamellae decurrent or subdecurrent. 



10. Pileus infundibuliform. 

 Pileus expanded- umbonate, yellow. 



11. Pileus convex to expanded. 

 Pileus becoming umbilicate or infundibuliform. 



12. Stipe glabrous. 

 Stipe fibrillose-striate. 



* Known from tropical America only. 



2. 



14- 

 20. 



3- 



7- 



4- 

 6. 



P. Infundibulum B. & C* 



5- 



P. levis B. & C. 



P. strigosus B. & C. 



P. conchattis Fr. 



P. troglodytes Fr.* 



8. 



11. 



P. connatus Berk.* 



9- 



P. Sullivantii Mont. 



10. 



P. concavus Berk.* 



P. illudens (Schw. ) Fr. 



12. 



13- 



P. Robinsonii B. & Mont. 



P. Cubensis B. & C* 



