Autor: Britton & Rose

Genus honouring Chevalier de Monville (Baron Hippolyte Boissel de Monville, 1794-1863), French botanist to whom we owe several descriptions of cacti. No portrait found.
A genus of pendulous, prostrate to semi-erect or decumbent plants, forming strongly branched bushes, with slender and elongated stems, bearing very small areoles. Ribs in variable number, usually few (6-9), tuberculate, with short and aciculate spines.
Flowers nocturnal, still open in the morning, with elongated tube, not felty nor spiny, only tiny scales, appearing near the tip of stems, white or yellow, the outer tepals tinged with green or pink, pollinated by bats during the night and hymenoptera in the morning. Fruits egg-shaped, glabrous, like a big plum, fleshy, juicy and wine red, with a white pulp. Seeds small, dark brown to black, more or less smooth. Dispersal of seeds probably assured in some regions by the tapir (Tapirus terrestris) and other mammals.
The genus Monvillea has a wide geographic distribution, and grows in more or less dry tropical forest under trees and shrubs, from 40 up to 2030 m in altitude, usually together with bromeliads (Tillandsia) and other cacti.
Argentina (Chaco, Formosa), Bolivia (Santa Cruz), Brazil (Mato Grosso, Mato Grosso do Sul, Minas Gerais), Paraguay (Alto Paraguay, Amambay, Boqueron, Central, Concepcion, Cordillera, Guaira, Itapua, Paraguari, Presidente Hayes).

Currently 6 species to debate + 2 subspecies:
– Monvillea cavendishii (Monv.) Britton & Rose 1920
– Monvillea estevesii (P.J.Braun) J.Lode 2013 (ex Cereus estevesii P.J.Braun 2004)
– Monvillea krapovickiana R.Kiesling 2010
– Monvillea phatnosperma (K.Schum.) Britton & Rose 1920
– Monvillea phatnosperma subsp. adelmarii (Rizzini & A. Mattos) J.Lode 2014
– Monvillea phatnosperma subsp. kroenleinii (N.P.Taylor) J.Lode 2013
– Monvillea saddiana Rizzini & A.Mattos 1985
– Monvillea spegazzinii* (F.A.C.Weber) Britton & Rose 1920

References: "TAXONOMY of the CACTACEAE" -  ISBN 978-84-617-3692-8 (Vol. 2)