Amaranthus

The red color of this flower is considered to be the darkest red naturally possible.

Amaranthus is a showy and exotic plant, ideal for beds and borders. Amaranthus are the best accent plants, especially in dried flower arrangements. The long, rope like Amaranthus flowers cascade to the ground from tall, erect branching stems. Amaranthus flowers are breathtaking tassels of the darkest red or green.

Kingdom
Plantae
Division
Magnoliophyta
Class
Magnoliopsida
Order
Caryophyllales
Family
Amaranthaceae
Genus
Amaranthus

Amaranthus is also called as Amaranth, Tampala, Tassel Flower, Flaming Fountain, Fountain Plant, Joseph's Coat, Love-lies-bleeding, Molten Flower, Prince's Feather and Summer Poinsettia. Amaranthus is a broad genus of about 60 species of short-lived herbs that breed mostly in the temperate and tropical regions. Amaranthus also includes the pigweeds, Amaranthus hybridus.
The plant is large and bushy, growing at about 90-130 cm in height. Many Amaranthus species are cultivated as leaf vegetables, cereals, or ornamental plants. It primarily serves as an annual ornamental, and its leaves and seeds are edible with nutritional properties.

Bisexual or unisexual, Amaranthus flowers are typically very small and usually prickly with bristly perianth and bracts. Bracts subtend the flower with two scarious or membranous bractlets . The flower's androecium holds usually 5 stamens located opposite the sepals. Its stamens on the are generally united for part or all of the length into a membranous tube or crown-like structure, sometimes with tiny appendages between the anthers. Leaves on the Amaranthus are alternate, simple, estipulate, and generally whole.

Source: http://www.theflowerexpert.com/content/growingflowers/flowersandseasons/amaranthus