Ocimum campechianum aka Least Basil

Ocimum campechianum is a small plant with a scent. It belongs to the mint family, Lamiaceae. It is native to tropical and subtropical parts of the Americas. Its range runs north from Argentina through Central America to Mexico. It also spans the Caribbean and reaches Florida. The RHS lists Ocimum micranthum as a synonym, or another name. Kew calls it an annual or subshrub. An annual lives one year; a subshrub has a woody base. Useful Tropical Plants calls it an annual. It has upright stems and few branches.

Plants reach about 0.7–1.6 feet [0.2–0.5 metres] tall. Useful Tropical Plants also gives a height of 1.3 feet [0.4 metres]. The leaves keep their scent when dry. People use the twigs for their scent, too. The supplied species accounts give no clear leaf shape or bark details. They do not state flower colour or when blooms appear. They do not describe the fruit. The RHS flower and leaf notes cover the genus, not this species.

Kew places this plant in a tropical climate with a dry season. In the Bahamas, it grows where people have disturbed the land. It grows on farmed ground there, too. In Guatemala, it grows in thickets and open fields. These sites range from moist to dry. It also grows on rocky slopes and by streams, on sand or gravel. Records from Guatemala reach about 4,265 feet [1,300 metres] above sea level. These sites do not show how much garden water it needs. Nor do they show its frost limits.

People gather wild plants for food, tea, and folk medicine. Leaves and tender stems add flavour to soups and stews. Dried leaves make a tea with a scent. In Guatemala, people use it for colds and stomach troubles. Accounts also report use against parasitic larvae, the young of parasites. These folk uses do not prove that treatments work or are safe. Useful Tropical Plants lists no known hazards. But it gives no clear check of safety for pets.

Other uses draw on scent and local customs. People rub leaves on horses to keep horseflies away. For scent, they tuck twigs under wristbands or rub them on shoulders. Maya uses include planting it near graves. They also keep plants in pots or on church altars. To grow new plants, sow seed with a light soil cover. The source says seeds sprout soon. Growers then pot the young plants and later plant them out. It gives no pest or disease guidance for this species.