Populus rotundifolia

Populus rotundifolia is in the willow or Salicaceae family and is endemic to Shaanxi, Gansu, Sichuan, Yunnan and Guizhou provinces in China, and Tibet. It grows up to 20 m tall.

• Leaves are deciduous, simple, large, broadly ovate-round, base wedge-shaped or nearly heart-shaped, 5.5–8.5 cm long and 5–8 cm wide, margin obtusely serrate, leaf green above, gray-green below, apex a long tapered point; both sides are white, pilose; petiole is flat, short, 3.5–6.5 cm long.
• Tree is dioecious tree (males and females on separate trees); flowers of both genders are green without petals and hang on cylindrical catkins, female catkin is 4–7 cm long, reaching 10 cm when ripe.
• Fruit is a 2-valved capsule, developing in May-June, opening to release many small seeds attached to cotton-like strands which carry the seeds in the wind to disperse them.
• Bark is gray-white, smooth; young branches are dark brown, hairy at first, smooth later, old branches gray; buds are ovate or conical, reddish-brown, with white, resinous scales.