- The plant known in Ancient Rome as costus is probably Saussurea lappa; see also Saussurea costus. Costus is also known by the botanical name Aucklandia lappa.
- A man named Costus is often held to be the father of Catherine of Alexandria. "Costus" in Greek means "from the East" referring to the Indian lower Himalaya from where the spice was imported into Rome and Greece.
Costus is a genus of perennial tropical herbaceous plants from the costus family (Costaceae). They are often characterized and distinguished from relatives such as Zingiber (true ginger) by their spiraling stems. The genus as a whole is thus often called spiral gingers, but this can also refer to C. barbatus specifically.
Costus spectabilis is the floral emblem of Nigeria; its flowers are represented (erroneously in red instead of yellow color) on its coat of arms. It is important not to confuse "Costus speciousus, C. spectabilis etc. with the herb known by the common name 'costus'. Some species are of importance to herbivores, such as caterpillars of the Restricted Demon (Notocrypta curvifascia) which feed on Crape Ginger (C. speciosus). The Crape Ginger is also a source of diosgenin, a compound used for the commercial production of various steroids, such as progesterone. On Trinidad and Tobago, a mix of Costus scaber juice and crushed Renealmia alpinia berries is used to treat dogs bitten by snakes.
Costus root has been used as an incense and perfume ingredient for thousands of years and is mentioned in Rabbinical writings as קשט koshet, reflecting its arrow head shape. It was used in Ketoret which is used when referring to the consecrated incense described in the Hebrew Bible and Talmud. It is also referred to as the HaKetoret (the incense). It was offered on the specialized incense altar in the time when the Tabernacle was located in the First and Second Jerusalem Temples. The ketoret was an important component of the Temple service in Jerusalem.
In Tibet it was and is used extensively as incense and medicine, and as an aromatic stomatic in Chinese herbal medicine under the name "Mu Xiang" meaning 'wood aroma'.
- Costus acreanus
- Costus barbatus – Spiral Ginger
- Costus chartaceus – Christmas Costus
- Costus cuspidatus (Nees & Mart.) Maas
- Costus deistellii
- Costus dubius
- Costus erythrocoryne
- Costus fragilis Maas
- Costus fusiformis Maas
- Costus giganteus, Giant Ginger
- Costus igneus
- Costus lima
- Costus ligularis
- Costus longebracteolatus
- Costus malortieanus
- Costus osae
- Costus phaeotrichus
- Costus phyllocephalus
- Costus potierae F.Muell.
- Costus pulverulentus
- Costus scaber
- Costus speciosus – Crape Ginger
- Costus spectabilis
- Costus spicatus – Spiked Spiralflag Ginger; Indian Head Ginger
- Costus tapenbeckianus
- Costus woodsonii
Formerly placed here
Plants for some time placed in this genus include Alpinia nutans (as Costus zerumbet)