| california single-leaf pinyon | (n) very small tree similar to Rocky mountain pinon but having a single needle per fascicle; similar to Parry's pinyon in range, Syn. Pinus californiarum |
| single-leaf | (n) pinon of southwestern United States having solitary needles and often many stems; important as a nut pine, Syn. single-leaf pinyon, single-leaf pine, Pinus monophylla |