Euphorbia hirta (sometimes called asthma-plant) is a pantropical weed, originating from the tropical regions of the Americas. It is a hairy herb that grows in open grasslands, roadsides and pathways. It is widely used in traditional herbal medicine across many cultures, particularly for asthma, skin ailments, and hypertension. It is also consumed in herbal tea form as folk medicine for fevers in the Philippines (where it is known as tawa-tawa), particularly for dengue fever and malaria.

 This erect or prostrate annual herb can grow up to 60 cm long with a solid stem that is furnished with many yellow to reddish coarse hairs, and produces an abundant white latex. There are stipules present. The leaves have an oblique base and are simple, elliptical to slightly rhombic, hairy (on both upper and lower surfaces but particularly on the veins on the lower leaf surface), with a finely dentate margin, the veins upperside being deep-set and conspicuous on the underside, and the leaf surface somewhat leathery. Leaves occur in opposite pairs on the stem. The flowers are unisexual and found in axillary cymes at each leaf node, held as dense balls of flowers and fruit capsules usually close to the stem, the flower glands with tiny white/pinkish petal-like appendages. The fruit is a capsule with three valves (creating 3 sides), uniformly appressed hairy, containing tiny (0.7–0.9 mm), oblong, four-sided orange to pink or red seeds. It has a white or brown taproot.

Taxonomy: Euphorbia hirta was given its scientific name by Carl Linnaeus in 1753. It continues to be classified in the genus Euphorbia within the family Euphorbiaceae. It has no accepted varieties, but has some among its synonyms.

Table of Synonyms	Name	Year	Rank	Notes
(Lag.) Small}}	1913	species	= het.
(L.) Millsp.}}	1909	species	≡ hom.
(Koidz.) H.Hara}}	1940	variety	= het.
(Koidz.) Hurus.}}	1954	form	= het.
Croizat}}	1943	variety	= het.
Hurus.}}	1954	form	= het.
(Boiss.) Millsp.}}	1916	species	= het.
(Koidz.) Makino & Nemoto}}	1925	variety	= het.
(Koidz.) H.Hara}}	1938	variety	= het.
Millsp.}}	1916	species	= het.
(L.) Raf.}}	1833	species	≡ hom.
(L.) Raf.}}	1838	species	≡ hom.
Miq.}}	1861	species	= het.
Lam.}}	1788	species	= het.
W.Fitzg.}}	1918	species	= het.
Lag.}}	1816	species	= het.
Kunth}}	1817	species	= het.
L.C.Wheeler}}	1939	variety	= het.
Koidz.}}	1919	variety	= het.
L.C.Wheeler}}	1939	variety	≡ hom., not validly publ.
Boiss.}}	1860	species	= het.
Steud.}}	1840	species	= het.
Jacq.}}	1760	species	= het.
Herter}}	1910	variety	= het.
Engelm.}}	1859	variety	= het.
Thell.}}	1917	variety	= het.
Chodat & Hassl.}}	1905	variety	= het.
(L.) Thell.}}	1917	variety	≡ hom.
Domin}}	1927	form	= het.
(Jacq.) Hitchc.}}	1893	variety	= het.
Domin}}	1927	form	= het.
Domin}}	1927	form	= het.
Vell.}}	1829	species	= het., nom. illeg.
Notes: ≡ homotypic synonym; = heterotypic synonym

Names: Euphorbia hirta has many common names including garden spurge, pillpod spurge, and hairy spurge. It is also called by the related names asthma weed, asthma plant and Queensland asthma weed. Additionally it is known as red milkweed and snakeweed.