THE PIXE SUB-FAMILY. 109 



from the Caucasian Mountains, and, according to Gordon, 

 the leaves are much broader, more glaucous, and longer 

 than any other variety of P. sylvestris. It is also very 

 robust, and grows to a great size. 



Var. argentea, Stevens. I* the Silvery Scotch Fir, 

 with the cones and leaves a beautiful, silvery, glaucous 

 color : a variety from the region of the Black Sea, where 

 it attains a large size. We believe this has not yet been 

 introduced into this country. 



There are other varieties mentioned by London and 

 others, that differ so little from the species as to be now 

 unrecognized ; such as var. Rigensis, var. Genevensis, etc. 



SECT. II. THREAT JE. THKEE LEAVES IN A SHEATH. 



20. P. australis. Michoux. LOXG-LEAVED OR SOVTH- 

 EKX YELLOW PIXE. Syn. P. palustris, Linnceus. Leaves, 

 10 to 15 inches long ; from a long, lacerated, light colored 

 sheath ; bright green color, and crowded in dense clusters 

 at the ends of the branches. Cones, from 6 to 10 inches 

 long, mostly cylindrical^ of a beautiful brown color, with 

 thick scales, armed with very small recurved prickles. 

 Seeds, large, oval, with a long wing. 



With the single exception of the White Pine, (P. Stro- 

 bus,) this species is perhaps the most valuable of the ge- 

 nus, and along our southern sea-board States, particularly 

 in Georgia and Florida, it is to be found in immense num- 

 bers, covering large tracts of sandy, barren soil, to 

 the almost total exclusion in many places of all other 

 plants. The size of the trees varies greatly according to 

 soil and situation. Along the roadsides and on sterile 

 spots, they are poor, stunted plants but a few feet in 

 height ; but as the soil becomes more congenial they 

 assume their proper proportions, averaging probably 75 



