Rivina humilis

Plants erect, straggling, or vinelike, 0.4-2 m, ± glabrous or densely pubescent. Leaves: petiole 1-11 cm; blade lanceolate, elliptic, or oblong to deltate or ovate, to 15 × 9 cm, base cuneate or rounded to truncate or cordate, apex acuminate or acute to obtuse or emarginate. Racemes 4-15 cm; peduncle 1-5 cm; pedicel 2-8 mm. Flowers: sepals white or green to pink or purplish, elliptic or oblong to oblanceolate or obovate, 1.5-3.5 mm; style often curved. Berries 2.5-5 mm diam. Seeds lenticular, 2-3 mm, enclosed in thin, densely pubescent membranes. 2n = 108.

Flowering year-round. Woods, hammocks, thickets, shell ridges, roadsides, disturbed areas; 0-1700 m; Ariz., Ark., Fla., La., N.Mex., Okla., Tex.; Mexico; West Indies; Central America; South America; Asia; Africa; Pacific Islands.

During enlargement and maturation of the fruit of Rivina humilis, the two inner cell layers of the pericarp become separated from the outer layers. The cells of the outermost two layers elongate centrifugally, eventually forming tubular trichomes 133-229 µm long. These two layers become appressed and adherent to the seed coat; thus the seed appears to be, and is sometimes described as, pubescent (J. W. Thieret 1966b). The outer layers of the pericarp differentiate into the juicy portion of the fruit (L. B. Kajale 1954; D. D. Nautiyal and S. C. Gupta 1984).

Rivina humilis is cultivated as a greenhouse plant or, in warm areas, as a garden ornamental. With its colorful berries, it is more attractive in fruit than in flower.

Plant: perennial subshrub; sometimes suffrutescent, 0.1-1 m high, puberulent; stems slender Leaves: petiolate, 3-11 cm long, deltoid to ovate, the apices acute to acuminate INFLORESCENCE: terminal or axillary, 3-15 cm long Flowers: white to pink, bracteate; calyx deeply 4-lobed, 2.0-3.5 mm long; stamens 4, distinct and alternating with the sepals; pistil 1-ovuled Fruit: FRUITS druplets; SEEDS black, lens-shaped Misc: Canyons and riparian habitats in oak woodland, grassland, and desertscrub; 800-1800 m (2700-5900 ft); Jun-Dec REFERENCES: Steinmann, Victor. 2001. Phytolaccaceae. J. Ariz. - Nev. Acad. Sci. Volume 33(1).

Steinmann 2001

Duration: Perennial Nativity: Native Lifeform: Forb/Herb General: Perennial or suffrutescent, 30-100 cm tall. Leaves: Ovate-acuminate, rounded to subcordate at base, 3-13 cm long, 1-5 cm wide, sparsely puberulent to glabrous, slender petioles 2-4 cm long, 2-4 cm long. Flowers: Inflorescence erect or somewhat curved, 3-8 cm long, rachis green, short-puberulent to sparsely pilose, bracteoles minute, sepals broadly elliptic, 2-3 mm long, pink or purplish with a greenish midvein, spreading; stamens about equaling or slightly shorter than sepals; flowers throughout year. Fruits: Sleek black, turning to red, shining or short-puberulent, 2.5-3 mm long. Ecology: Shade of shrubs and trees in moist places, along watercourses or on flats; 1,500-4,500 ft (457-1372 m). Distribution: s AZ, NM TX, OK, AR, LA, FL; south to s MEX, and in S. Amer.; Africa; Asia and Australia. Notes: Often found where water stands during the rainy season and in very shady areas. Distinct by the large, broad, entire leaves, and spikes with pink flowers followed by bright red berries. Ethnobotany: Unknown Etymology: Rivina has a root in the word for along streams, humilis means low-growing or humble. Synonyms: None Editor: SBuckley 2010, FSCoburn 2015