veinlets

/ˈveɪnlɪts/
noun
  1. Very small veins, especially in leaves, rocks, or the body.
    • The leaf's veinlets carried water to every part of the plant.
    • Under the microscope, the veinlets in the insect's wing were clearly visible.
    • The geologist pointed out the thin veinlets of gold running through the quartz.