Costus

Costus is a genus of herbaceous perennial plants in the family Costaceae, erected by Linnaeus in 1753. It is widespread through tropical and subtropical regions of Asia, Africa, and the Americas.

Costus is often characterized and distinguished from relatives such as Zingiber (true ginger) by its 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 speciosus, 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 Costus speciosus (crêpe ginger). The crêpe ginger is also a source of diosgenin, a compound used for the commercial production of various steroids, such as progesterone. In Trinidad and Tobago, a mix of Costus scaber juice and crushed Renealmia alpinia berries is used to treat dogs bitten by snakes.

Species
, Plants of the World Online recognises 115 species, as follows: • Costus acanthocephalus

• Costus acreanus

• Costus acutissimus

• Costus adolphi-friderici

• Costus afer

• Costus albiflos

• Costus alfredoi

• Costus allenii

• Costus alleniopsis

• Costus alticola

• Costus amazonicus

• Costus antioquiensis

• Costus arabicus

• Costus asplundii

• Costus asteranthus

• Costus atlanticus

• Costus aureus

• Costus barbatus

• Costus beckii

• Costus bicolor

• Costus bracteatus

• Costus bullatus

• Costus callosus

• Costus chartaceus

• Costus chrysocephalus

• Costus claviger

• Costus clemensiae

• Costus cochabambae

• Costus comosus

• Costus convexus

• Costus cordatus

• Costus cupreifolius

• Costus curvibracteatus

• Costus dendrophilus

• Costus dinklagei

• Costus dirzoi

• Costus douglasdalyi

• Costus dubius

• Costus eburneus

• Costus elegans

• Costus erythrocoryne

• Costus erythrophyllus

• Costus erythrothyrsus

• Costus fenestralis

• Costus fissicalyx

• Costus flammulus

• Costus fortalezae

• Costus gabonensis

• Costus geothyrsus

• Costus gibbosus

• Costus giganteus

• Costus glaucus

• Costus gracillimus

• Costus guanaiensis

• Costus juruanus

• Costus kupensis

• Costus laevis

• Costus lasius

• Costus lateriflorus

• Costus ledermannii

• Costus leucanthus

• Costus ligularis

• Costus lilaceus

• Costus lima

• Costus loangensis

• Costus longibracteolatus

• Costus louisii

• Costus lucanusianus

• Costus maboumiensis

• Costus macranthus

• Costus microcephalus

• Costus mollissimus

• Costus montanus

• Costus mosaicus

• Costus muluensis

• Costus nimba

• Costus nitidus

• Costus obscurus

• Costus oligophyllus

• Costus oreophilus

• Costus osae

• Costus phyllocephalus

• Costus pictus

• Costus pitalito

• Costus plicatus

• Costus plowmanii

• Costus prancei

• Costus productus

• Costus pseudospiralis

• Costus pulverulentus

• Costus quasi-appendiculatus

• Costus ricus

• Costus rubineus

• Costus rumphianus

• Costus scaber

• Costus schlechteri

• Costus sepacuitensis

• Costus spectabilis

• Costus spicatus

• Costus spiralis

• Costus sprucei

• Costus stenophyllus

• Costus sulfureus

• Costus talbotii

• Costus tappenbeckianus

• Costus ulei

• Costus vargasii

• Costus varzearum

• Costus villosissimus

• Costus vinosus

• Costus whiskeycola

• Costus wilsonii

• Costus woodsonii

• Costus zamoranus

• Costus zingiberoides

Numerous other species have been called Costus over the years, but are now regarded as members of other genera. Such genera include Alpinia, Amomum, Caulokaempferia, Cheilocostus, Chamaecostus, Dimerocostus, Hellenia, Paracostus, Renealmia, Tapeinochilos, etc.
 * Formerly placed here