Parodia tenuicylindrica is a species of cactus from the genus Parodia. The small green cacti have yellow and red-brown spines, white wool and yellow flowers. They produce yellow-green fruit, and black seeds. P. tenuicylindrica can be found growing individually in Rio Grande do Sul, Brazil.
The species was originally described as Notocactus minimus by Frič & Kruizinger in 1940, based on a description by Bruining. It was later described as Notocactus tenuicylindricus by Friedrich Ritter.[1] Despite objections from hobbyists (among whom Notocactus species were popular) Notocactus (and others) were synonymised under Parodia.[2] In 1997, based on Ritter's earlier description, D. R. Hunt classified the species as Parodia tenuicylindrica.[1]
Parodia tenuicylindrica are cylindrical cacti which are green to blue-green.[1] In height, they are 4cmto8cmcm (02inchesto03inchescm) and are from 2cmto3cmcm (01inchesto01inchescm) in width.[1] The plants have 13-21 notched and tuberculate ribs.[1] On top of the tubercles, there are areoles with white wool. The species has straight and stout spines; the radial spines, of which there are between ten and fifteen, are pale yellow, and between 3mm4mm in length, while the 2-4 red-brown central spines are between 3mm6mm long.[1] The species produces lemon yellow flowers (which are up to 4.3cm (01.7inches) long) and greenish-yellow fruits. The seeds are black oblongs with tubercles.[1]
Parodia tenuicylindrica can be found growing solitarily in Rio Grande do Sul, Brazil.[1] It is currently classified as Endangered (EN) on the IUCN Red List, with major threats reported to be fires, cattle grazing due to trampling, agriculture, and forestry.