4- PiNUS MONOPHYLLA Torr. and Frem., Fremont's 2d Rep. 319, 



t. 4. 1845. 



5-12 m. high, branched from or near the base; leaves single, 

 in pairs, or (very rarely) in threes, 2-5 cm. long; cones sessile, 

 subglobose, 4-6 cm. long; tips of scales thick, truncate, awnless; 

 seeds large, brown, wingless, edible. Pinon or Nut Pine. 



Texas, Colorado, Utah to Arizona. 



The form in which all the fascicles contain 2-3 leaves should 

 be referred to the variety P. monophylla edulis. 



4a. PiNUS MONOPHYLLA EDULIS (Engelm.) Joncs, Zoe II. 1891. 



Mr. Jones seems to have made proper disposition of this 

 species in a report on the Flora of Utah, published in Zoe, 1891, 

 reducing it to a variety of P. monophylla. Specimens of P. 

 monophylla have been found in which there are actually more 

 bundles with two leaves than with one, and these intermediate 

 forms are frequent. P. edulis, therefore, seems to be a variety 

 of P. monophylla in which all of the fascicles have two leaves 

 (in very rare cases, three). So far as the sections of P. edulis 

 and the two-leaved form of true P. monophylla are concerned, 

 there is practically no difference. The variety edulis appears 

 to have fewer rows of stomata than the species, but this character 

 is not invariable. The sclerenchyma in the latter is often 

 thicker than in the former, but not always. 



The descriptions of the two trees, as given in Britton's "Trees 

 of North America," coincide exactly, except for two points: 

 in the description of P. edulis we find "leaves in sheathless 

 fascicles of 2 or* 3, triangular or nearly round, dark green, stout, 

 1.8 to 4 cm. long, entire," etc.; in the description of P. mono- 

 phylla we find "leaves are solitary and round, rarely two or 

 three in a sheathless fascicle, triangular, pale green and glaucous, 

 round and stout, about 4 cm. long," etc. Now in the herbarium 

 material that I have examined, numerous specimens of P. 

 edulis may be found in which the leaves are "pale green and 

 glaucous," in some cases as pale as, or even paler, than some of 

 our specimens of P. monophylla. This differenc, therefore, does 

 not seem to be fixed. I have already spoken of the intermediate 

 leaf forms, because of which Mr. Jones reduced P. edulis to 



