All plants produce spikes of upright, brightly coloured flowers well above the foliage, in shades of red, orange and yellow, often bicoloured.

[5] The flowers produce copious nectar while blooming and are attractive to bees and sunbirds.

[7] The name honours Johann Hieronymus Kniphof, an 18th-century German physician and botanist.

[8] As of February 2025[update], Plants of the World Online accepted 73 species, including two hybrids.

In addition to the species, many named cultivars of mixed or uncertain parentage have been selected for garden use.