Picea martinezii, the Martinez's spruce, is a medium-sized evergreen tree growing to 25–35 m tall, and with a trunk diameter of up to 1 m. It is native to northeast Mexico, where it occurs at six localities in the Sierra Madre Oriental mountains in Nuevo León. It grows at moderate altitudes from 2150–2600 m, growing along streamsides in mountain valleys, where moisture levels in the soil are greater than the otherwise low rainfall in the area would suggest.
left|thumb|Tree at El Butano, Nuevo León, Mexico
The bark is thin and scaly, flaking off in small circular plates 5–10 cm across. The crown is conic, with widely spaced branches with drooping branchlets. The shoots are stout, pale buff-brown, glabrous, and with prominent pulvini. The leaves are needle-like, 23–35 mm long, stout, moderately flattened in cross-section (but unlike other spruces, flattened from side-to-side, not top-to-bottom), bright glossy green with inconspicuous lines of stomata; the tip is viciously sharp.
The cones are pendulous, broad cylindrical, 8.5–16 cm long (the largest of any North American spruce) and 3 cm broad when closed, opening to 6 cm broad. They have stiff, smoothly rounded scales 2-2.5 cm broad, and are green, maturing pale brown 6–8 months after pollination. The seeds are black, 4–8 mm long, with a 15–23 mm long pale brown wing.