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| The genera of Cactaceae |
~ Monvillea, cf. Hunt(1967)
The plants cerioid; not ‘low and very compacted’. The stems spiny; elongate cylindric. The plants terrestrial and self supporting; mostly unbranched; leaning to more or less erect; shrubby; to 1–4 m high. The branches cylindrical. The stems not segmented; ribbed and grooved. The ribs 8–13; longitudinal; flattened or narrow. The plants not conspicuously tuberculate. The areoles not tubercle-associated; borne in longitudinal series (along the ribs); simple; grey- to white- woolly; with spines. The spines clustered; 10–22; 0.6–4 cm long; with radials and centrals differentiated (the centrals longer). Central spines 1–4. Radial spines 10–18. The spines stiff; straight; terete (acicular). The mature stems leafless.
Flowering at night. The flowers lateral; one per areole; conspicuously curved, shortly funnelform to campanulate; sessile; medium-sized to large; 5–6.5 cm long; conspicuously curved, somewhat irregular (the tubes bent upwards and the mature anthers lying abaxially on the perianth). The receptacle conspicuously produced beyond the ovary into a tubular hypanthium. The pericarpel like the tube, with fleshy scales and naked areoles. The hypanthial tube bearing conspicuous, fleshy scales and naked areoles; not naked; with scales (these fleshy). The axils of the scales of the hypanthial tube more or less naked. The hypanthial tube spineless. The perianth white, or green to white; limb relatively large to short or none. The perianth segments spreading (widely so); relatively short, broad; blunt to pointed. Stamens numerous; adnate to the perianth; in groups (with a circle in the throat).
The mature fruit to 1.5 cm long; ovoid, or pyriform; green, or purple; indehiscent. The seeds not encased in bony arils; with hilum and micropyle conjunct. Cotyledons reduced or vestigial.
Natural Distribution. Eastern Brazil.
Classification. 2 species. Subfamily Cactoideae. Tribe Cereeae.
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2018 onwards. The genera of Cactaceae: descriptions, illustrations, identification, and information retrieval. Version: 14th November 2021. delta-intkey.com’.
