The flowers of Giant-trumpets (Macromeria viridiflora) are trumpet-shaped, but they aren't exactly giant.
The tubular, yellow-green flowers have 5 pointed lobes and are only about 2.5 inches (6.4 cm) long here in Arizona. However, the flowers are variable in size and those in Mexico are larger. The flowers are covered in a white fuzz and hang in drooping clusters at the branch tips.
The lanceolate leaves are hairy, alternate, and have prominent veins running down the leaves. The lower leaves are largest, with the leaves gradually becoming smaller higher up on the plants.
These native perennials are in the Borage Family (Boraginaceae) and can grow up to 3 feet (91 cm) tall. They are found growing in clearings and canyon areas in coniferous forests in Arizona or New Mexico, as well as northern Mexico at elevations above 6000 feet (1829 m). I found these plants growing along the road in the town of Summerhaven in the Santa Catalina Mountains this last summer.