258 BOTANY. 



3-4£' long-, squarrose by the more or less protruding thin-edged scales, the 

 free part of which is rounded or more or less triangular, rarely reflexed; 

 seeds 5 or 6" long, somewhat angled, with a narrow deciduous wing-rim; 

 cotyledons 6-7. 



Var. a. serrulata. — Leaves slender, slightly and distantly serrulate, and 

 as in the two following varieties, with few or scarcely any stomata on the 

 back; cones of the ordinary form. 



Var. /?. macrocarpa. — Leaves slender, entire; cones cylindric, 6-8' 

 long, 2J' in diameter, the apophysis of the scales short, rounded. 



Var. ;/. reflexa. — Leaves as in last; cones ovate-cylindrical, about 4' 

 long; apophysis elongated, reflexed. 



A middle-sized tree, rarely more than 50 feet high, on the higher 

 mountains of Colorado, New Mexico, and Arizona, extending to Southern 

 California. Var. a was found by Dr. Rothrock on Mount Graham (783) ; 

 var. y, by the same, on Santa Rita Mountain (east of Tucson) and in the 

 Sanoita Valley (654 and 1001). The cone of 1001 resembles that of the 

 Asiatic P. Koraiensis, or of a small P. Ayacalvuite from Mexico. Var. /? was 

 collected on the San Francisco Mountains by Mr. Ferdinand Bischoff in 

 1871. — The species is intermediate between the true Strobi and Cenibra; of 

 the former it has the peripheral resin-ducts, usually 2, on the dorsal side; 

 with the latter it has the large, almost wingless seeds in common; from 

 both it is distinguished by the back of the leaf being marked b} r a single, 

 or a few series of stomata. It thus becomes the type of a third section of 

 the Strobus-like Pines, which may be arranged as follows : 



1. Cembrce, with large, almost wingless seeds; dorsal face of leaves with- 

 out stomata; resin-ducts of the serrulate leaves imbedded in the parenchyma; 

 P. Cenibra of Europe and Asia with appressed, and P. Koraiensis of Northeast- 

 ern Asia with squarrose cone-scales. 2. Flexilcs, with similar seeds, but entire 

 or nearly entire leaves, with a few series of stomata on back, with peripheral 

 ducts; P. flexilis, P. albicauUs, and the Asiatic P. pygmoia. This last is thus 

 entirely distinct from P. Cembra, as a variety of which it has long been 

 considered by Parlatore and other botanists, while P. Mandsclmrica, at least 



the aiuents and the terminal bud. Wben, in the following season, the axis elongates, while the annul, 

 matures to a cone, this latter naturally becomes quite lateral, but we continue to designate it as sub- 

 terminal, in relation to its own, coetaneous, part of the axis. 



