Common name: Stepladder ginger, Spiral flag, Spiral ginger, Velvet costus, Gengribre-espiral, Bandeira-espiral, Cana agria
Stepladder ginger plants are common ornamental plants in Indian gardens because of their broad velvety leaves and spiral stems. These plants grow to a height of .8-1 meter with a thick green stem that grows in a spiral shape, giving the plant its name Spiral ginger.
Leaves are 20-30 cms long, about 20 cms broad and dark green. They have fine hairs on the upper surface, giving the leaves a velvety texture. Stepladder ginger leaves are spirally arranged along the stem, and looks very ornamental when they curve around in hairpin-like spirals.
Inflorescence is usually terminal, at the tips of the stem. They are globular spikes made up of green bracts each of them holding a flower. But only one or two flowers are open at a time. Stepladder ginger flowers have a beautiful red and yellow pattern. They are tubular with 2 large petals towards the top, and 3 smaller ones towards the lower half.
These flowers attract bees and hummingbirds that help pollinate them. Fruits are white capsules that are about 1 cm in diameter with many black seeds contained inside.
Stepladder ginger roots are rhizomatous, producing small plants from the sides of the parent plant. Left to itself, Stepladder ginger plants can produce clumps of foliage made up of beautiful, green, velvety leaves.
These plants are easy to grow, on the ground or in pots since they require very little maintenance. They can grow in partial shade, and are tolerant of drought, pollution, heavy rains and fluctuating weather. They need good sunlight to bloom and produce fruits.
Costus plants are known for their medicinal and anti-diabetic properties, according to Ayurveda and traditional herbal medicine. Costus speciosus and Costus igneus plant roots are used in treatment of diabetes and are sometimes called insulin plants. Roots of stepladder ginger plants also have antioxidant and antidiabetic properties.
Propagation is through seeds, stem cuttings or by replanting small plants that grow from the roots of the parent plant.