Parodia warasii

Parodia warasii is a cactus from southern Brazil. Its native range lies within Rio Grande do Sul. It belongs to the cactus family, Cactaceae. Wild plants grow in cracks on steep rock faces. These sites lie within Araucaria and deciduous forests. The species has a small range, with four known locations. Landslides linked to farm erosion threaten its wild populations. Dams and rock sports pose further possible threats.

This cactus forms a short, upright column with age. Some plants stay single; others form tight basal clumps. Garden accounts give heights of 1.5–1.6 feet [0.46–0.5 metres]. LLIFLE also reports larger plants reaching 2 feet [0.6 metres]. Stems measure about 0.3–0.5 feet [0.1–0.15 metres] across. The same source gives an extreme diameter of 1 foot [0.3 metres]. The glossy green stems lack a blue-grey cast. Each has 15–16 straight ribs with slight humps. White areoles bear rows of fine, flexible spines. Their shades range from gold through yellow-brown to brown.

Large yellow flowers open near the stem's crown. Their colour ranges from gold to pale lemon. Each bloom spans about 0.16–0.2 feet [0.05–0.06 metres]. The petals have wavy edges and fringed tips. Their deeper yellow bases fade towards the ends. White wool and bristles cover the flower tubes. Chicago Botanic Garden lists flowering from March through June. LLIFLE places the bloom season in summer. The small seeds have glossy black coats and a pouch-like shape.

Give this cactus warmth, bright light, and free drainage. LLIFLE favours partial shade and warns against full sun. Chicago Botanic Garden lists both sun and partial shade. Use a gritty mix with neutral to slightly acid pH. Water and feed during summer; LLIFLE favours rainwater. Keep the plant much drier through winter. Cold, wet compost can cause rot and root loss. LLIFLE advises keeping temperatures above freezing. Chicago Botanic Garden lists USDA zones 8–11, a broader hardiness claim.

Its upright stems suit use as a specimen plant. The rib pattern, coloured spines, and crown flowers provide interest. LLIFLE rates it as easy to grow under suitable conditions. Growers can raise it from seed or available cuttings. The supplied sources give no food or medicinal uses. They also provide no firm evidence about toxicity.