PINACEAE 



Mexican Pin yon. Nut Pine 



Pinus cembroides Zucc. 



HABIT. A tree 10-40 feet high and 1-2 feet in diameter 

 (max. 50 by 3 feet) ; bole often divided with a spreading, rounded 

 crown, giving the tree a bushy appearance. 



LEAVES. In fascicles of 3, or 2 and 3 (rarely from 1 to 5); 

 1-2 inches long; moderately slender (less than 1 mm.); blue- 

 green; incurved; sharp-pointed; persistent 3-4 years; margins 

 with minute teeth; fascicle sheath only partially deciduous. 



FLOWERS. Male yellow in crowded clusters; female red. 



FRUIT. Cone 1-2|/^ inches long; ovoid to globose; scales 

 few and unarmed. Seed: Yi-V^ inch long, wingless, edible, hard- 

 shelled. 



TWIGS. Moderately stout; orange-colored to brown. 



BARK. Rarely over Yz inch thick on mature trees; divided 

 into ridges separated by shallow fissures; light red-brown. 



WOOD. Unimportant; rather hard; fine-textured; light 

 yellow heartwood; used locally for fuel, ties, and posts. 



SILVICAL CHARACTERS. Very intolerant; growth slow; 

 maturity reached in 250-350 years; reproduction generally 

 sparse and scattered; tree very windfirm. 



HABITAT. Upper Sonoran zone; arid, gravelly slopes; usually 

 in mixture with junipers and scrub oaks. 



* * * 



The following species are very similar to Pinus cembroides 

 but differ from it in distribution and the following characters: 



Pin YON. Colorado Pin yon 



Pinus edulis Engelm. (Pinus cembroides var. edulis Voss) 

 LEAVES. In fascicles of 2 (rarely 1 or 3) ; over 1 mm. thick; 

 yellow-green; persistent 3-9 years; margins entire. 



FRUIT. Seed thin-shelled, easily cracked with teeth. 



Singleleaf Pinyon 

 Pinus monophylla T. & F. {Pinus cembroides 

 var. monophylla Voss) 

 LEAVES. Single (rarely in 2's); over 1 mm. thick; pale 

 green; persistent 4—12 years; margins entire. 



Parry Pinyon 



Pinus quadrifolia Pari. {Pinus cembroides var. parryana Voss) 

 LEAVES. In fascicles of 4 (rarely 3-5; over 1 mm. thick; 

 blue-green; persistent 3 years; margins entire or toothed. 



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