''Acmella'' is a genus of plants in the family

Asteraceae The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae ...

, described as a genus in 1807.Tropicos, ''Acmella'' Pers.
/ref> It is native to the Americas and has been introduced to Asia, Africa, the Pacific islands, and Australia. One familiar species is ''

Acmella oleracea ''Acmella oleracea'' is a species of flowering herb in the family Asteraceae. Common names include toothache plant, Szechuan buttons, paracress, buzz buttons, tingflowers and electric daisy. Its native distribution is unclear, but it is likely de ...

'', which has been widely cultivated for centuries. It is used for food and

medicine Medicine is the science and Praxis (process), practice of caring for a patient, managing the diagnosis, prognosis, Preventive medicine, prevention, therapy, treatment, Palliative care, palliation of their injury or disease, and Health promotion ...

, and as an insecticide and an

ornamental plant Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that ...

. Its common use as an herbal remedy for

toothache Toothache, also known as dental pain,Segen JC. (2002). ''McGraw-Hill Concise Dictionary of Modern Medicine''. The McGraw-Hill Companies. is pain in the teeth or their supporting structures, caused by dental diseases or pain referred to the t ...

and oral infections earned it the nickname toothache plant. These are annual or perennial herbs with branching stems usually reaching 10 to 20 centimeters in length, growing prostrate or erect. The oppositely arranged leaves are smooth-edged or toothed, and usually have rough or soft hairs. The

flower heads A pseudanthium (Greek for "false flower"; ) is an inflorescence that resembles a flower. The word is sometimes used for other structures that are neither a true flower nor a true inflorescence. Examples of pseudanthia include flower heads, compos ...

are usually solitary at the tips of the stem branches, or occasionally borne in

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed ...

s. There are several to many disc florets with bell-shaped throats and 4 or 5 triangular lobes, usually yellow, or sometimes orange. Some species lack ray florets, but some have 5 to 20 or more, usually in yellow or orange, but occasionally white or purple. The disc florets are bisexual, but any ray florets are

pistillate Gynoecium (; ) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) '' pistils' ...

Species

; Accepted species

References

External links

*
GRIN Species Records of ''Acmella''.
Germplasm Resources Information Network (GRIN). Asteraceae genera {{Heliantheae-stub