Single-leaf Piñon

Pinus monophylla

Observed on Mt. Ord, eastern Maricopa Co., Arizona, USA. July 2011.

CONES: The seed cones are short and nearly spherical with an abundance of sticky resin and thick, hard scales. The seeds are very large. The male cones are much smaller, the scales are papery, release pollen, and are located in dense slusters at the branch tips (image below).

LEAVES: Leaves are stiff, nearly round in cross-section, and with a papery sheath surrounding the attachment to the stem - but usually only one leaf per such fascicle.

TREE: A maturity a medium sized tree 4 to 12 meters tall. Sometimes rather shrubby with branches arising low on the bole.

RANGE: Single-Leaf Pinyons range from the upper elevations of chaparral habitat on up into ponderosa woodland where they tend to occur on drier, thinner soil areas. Pinyons very often grow in the same habitats as one or more species of juniper. This tree is especially characteristic of mid elevations in northwestern Arizona, but populations range into central Arizona.

UNARMED. The twigs and branches are without thorns, but the needles are plenty sharp.

Pinaceae -- Pine Family

More Information:

• Southwest Environemtnal Information Network
• USDA Plant Profile
• ITIS Taxonomic Report
• Wikipedia
• Google Images
• Google Scholar Literature Search

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Male Cones of Single-leaf Piñon