Amarillo is an erect, smooth, branched, rank-smelling herb, 0.3 to 0.8 meters high. Leaves are 4 to 7 centimeters long, deeply pinnatifid with linear-lanceolate segments. Heads are solitary, 1.5 to 2 centimeters in diameter, borne on long peduncles, which are thickened upward. Flowers are pale to deep yellow, sometimes red. Species is similar to ahito (Tagetes erecta) except that it is smaller, with finer leaves and smaller heads.
- Cultivated for ornamental purposes in the Philippines.
- Thoroughly naturalized in Lepanto and the Benguet Subprovinces, along gravel banks and streams, at altitudes of 1,200 to 1,500 meters.
- Native of Mexico.
- Now widely distributed in cultivation.
- Flowers yield a yellow crystalline substance, quercetagetine. The dye was found several shades browner than quercetin.
- Flowers contain volatile oil, 0.57%.
- Fruit contains phytomelan, 3.2%.
- Study of roots, leaves and flowers yielded thiophenes, steroidal and terpenoidal type constituents.
- Flowers considered carminative.
- Considered aromatic, digestive, diuretic and sedative.
- Flowers used in refreshing drinks.
- Leaves and essential oil used as food flavoring.
- Flowers considered carminative and refreshing. Decoction of flowers used to relieve flatulence.
- Used for treatment of indigestion, colic, severe constipation, coughs, dysentery.
- Externally, used for sore eyes and rheumatism.
- Dye: Dried flowers used as adulterant of saffron, used for coloring foods yellow. Also used for coloring textiles.
- Insecticidal: Secretion from roots have an insecticidal effect on the soil, against nematodes and keeled slugs.
- Repellent: Repels insects (whiteflies).
• Larvicidal: Study of T patula essential oil on fourth instar larvae of mosquito species showed greatest activity against A aegypti, followed by An. stephansi and C quinquefasciatus. Results were compared to synthetic insecticide, malathion.
• Nematicidal: Extract of yellow flowers was studied to identify phytochemicals lethal to economically important cyst nematode Heterodera zeae. Phytochemical analysis yielded phenolic compounds (flavonoids and phenolic acids). Results showed crude extracts to have promising nematicidal activity. Commercially obtained α-terthienyl and gallic and linoleic acids showed 100% mortality at concentrations of 0.125% after 24 h.
• Antibacterial / Patuletin: Study showed the methanol extract of the flower to possess antimicrobial activity against a number of bacteria. Study isolated a flavonoid patuletin as the active antibacterial principle.
• Antimicrobial: Study of various extracts evaluated the antimicrobial activity of T. erecta and T. pistula flowers. Results showed the extracts of both species possess potential broad spectrum antibacterial activity.
• Hypotensive / Hypertensive Effects: Study of methanolic extract of roots of Tagetes patula isolated well known citric and malic acid as hypotensive, and pyridine hydrochloride as a hypertensive constituent.
• Sesquiterpene Rich Volatile Seed Oil: Study of hydrodistilled volatile seed oil yielded forty constituents, comprising 94% of the total oil. The constituents of the volatile oil were (E)-caryophyllene, caryophyllene oxide, germacrene D, (Z)-ß-ocimene and limonene. The chemical composition was characterized as sesquiterpene and a-terthienyl rich with appreciable biocidal (insecticidal and nematicidal) and pharmacological potential.
Extracts and other products in the cybermarket.