Tuesday, May 27, 2014

Pinus cembrioides - Pinyon Pine

Uncommonly seen pinyon pine tree. Only one I have seen is in the parking lot of the Sesnon House on the Cabrillo Campus. The pinyons are very hard to differentiate from one another and I have based my identification on the fact that this specimen has a mixture of 2 (mostly) and 3 (a few) needles in their bundles.

The pinyon pine is a small pine, growing 15-20' in cultivation. Usually with branches to the ground, this one was lifted. Generally full canopy with an oval habit. Pinyons are very popular with wildlife.





Needles are in bundles of 2 and occasionally 3's. They are 1-2" long, stiff, pointing forward, light to medium green, with stomates on both surfaces but mostly on the upper.



This image shows 2 and 3 needles and the white stomatal bands on the upper surface (towards the inside of the bundle). Also notice that lack of the bundle sheath, they are deciduous on these pinyon pines.



Stems slightly hairy lacking bundle sheaths. Fairly stout and stiff.



Buds small, tan, slightly pointed. Stems are gray.



Cones are small, oval in shape 1-1.5", opening to reveal large oblong rounded seeds with no wings. Open cones are about 2" across.



Misidentification:
Other pinyon pines. Not sure I can tell the difference between P. cembroides and P. edulis.

Location:
Aptos
Cabrillo College Sesnon Parking lot.