Red Canna plants are known for their vibrant, red flowers and broad, green foliage. They typically have large, zygomorphic flowers with three sepals and three petals, which can range in color from red to yellow-orange, depending on the variety. The petals are usually erect and can be 4-6.5 cm long. The bracts (modified leaves surrounding the flower) are also green or have shades of yellow, orange, and red to pink, according to Wikipedia. 

Here's a more detailed description:

Flowers:

The flowers are hermaphrodite and often large, with a unique structure. The sepals are triangular and 1-1.7 cm long, and the petals are erect and 4-6.5 cm long. 

Leaves:

Canna plants have large, broad, green leaves that grow from the base of the plant, creating a dense, leafy display. 

Stems:

The stems are upright and sturdy, supporting the leaves and flowers. 

Growth Habit:

Red canna plants are known for their vigorous growth, often creating clumps of foliage and flowers. 

Flowering Period:

In their natural habitat, canna plants typically bloom in the months of August to October. 

Pollination:

Canna flowers have a specialized pollination mechanism, with insects playing a key role in transferring pollen.