Pilea cadierei (aluminium plant or watermelon pilea) is a species of flowering plant in the family Urticaceae, native to China and Vietnam. It is an evergreen perennial growing up to 30 cm (12 in) tall by 21 cm (8 in) broad, with dark green oval leaves, each leaf having four raised silvery patches (hence the name "aluminium plant"). With a minimum temperature of 15°C (59°F), it is cultivated as a houseplant in temperate regions. It has gained the Royal Horticultural Society's Award of Garden Merit. The specific epithet cadierei refers to the 20th-century botanist R.P. Cadière.