Rivina humilis

Rivina humilis is a species of flowering plant in the family Petiveriaceae. It was formerly placed in the pokeweed family, Phytolaccaceae.^[2] It can be found in the southern United States, the Caribbean, Central America, and tropical South America. Common names include dogblood, pigeonberry,^[1] rougeplant,^[1] baby peppers,^[3] bloodberry,^[1] and coralito.^[1] The specific epithet means "dwarfish" or "lowly" in Latin, referring to the plant's short stature.^[4]

Rivina humilis
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Order:	Caryophyllales
Family:	Petiveriaceae
Genus:	Rivina
Species:	R. humilis
Binomial name
Rivina humilis L.
Synonyms
Rivina laevis L.[1]

Description

Pigeonberry is an erect, vine-like^[5] herb,^[3] reaching a height of 0.4–2 m (1.3–6.6 ft).^[5] The leaves of this evergreen perennial^[6] are up to 15 cm (5.9 in) long and 9 cm (3.5 in) wide, with a petiole 1–11 cm (0.39–4.33 in) in length. Flowers are on racemes 4–15 cm (1.6–5.9 in) long with a peduncle 1–5 cm (0.39–1.97 in) in length and pedicels 2–8 mm (0.079–0.315 in) long. Sepals are 1.5–3.5 mm (0.059–0.138 in) in length and white or green to pink or purplish.^[5] The fruit is a glossy, bright red berry^[4] 2.5–5 mm (0.098–0.197 in) in diameter.^[5]

Rivina humilis plant with fruit and flowers.

Habitat

Rivina humilis can be found in forests, thickets, shell middens, hammocks, roadsides, and disturbed areas at elevations from sea level to 1,700 m (5,600 ft).^[5] It requires less than partial sun and is tolerant of full shade. It is also tolerant of salt spray and saline soils.^[6]

It is considered invasive in New Caledonia, where it was likely introduced in 1900.^[7] It is considered a weed in Queensland, Australia where it has naturalised, and is also naturalised on Cocos Islands, Réunion, Norfolk Island, Fiji, Tonga, French Polynesia, Hawaii, India and the Galapagos Islands.^[8]

Uses

Pigeonberry is cultivated as an ornamental in warm regions throughout the world^[5] and is valued as a shade-tolerant groundcover.^[9] It is also grown as a houseplant^[10] and in greenhouses.^[5]

The juice made from the berries was used as a dye and ink at one time. The berries contain a pigment known as rivianin or rivinianin,^[4] which has the IUPAC name 5-O-β-D-Glucopyranoside, 3-sulfate, CAS number 58115-21-2, and molecular formula C₂₄H₂₆N₂O₁₆S.^[11] It is very similar to betanin, the pigment found in beets.^[4] The fruit also contains the betaxanthin humilixanthin.^[12]

The juice of the berries have been tested in male rats and are reported to be safe to consume.^[13]

Ecology

R. humilis is a host plant for the caterpillars of Goodson's greenstreak (Cyanophrys goodsoni)^[14]