Parodia concinna aka Sun Cup

Parodia concinna is a small cactus known as sun cup. It belongs to the cactus family, Cactaceae. Its native range spans southern Brazil and much of Uruguay. In Brazil, it grows in Rio Grande do Sul. It lives on rocky outcrops within grasslands called pampas. Wild plants face threats from grazing, illegal collecting, and eucalyptus planting. LLIFLE reports that wild populations are shrinking across its range.

The stem forms a round ball with a flattened top. It can grow longer as it ages. Mature plants reach about 0.33 feet (0.1 m) tall and wide. The RHS gives five to ten years to reach maturity. The glossy stem ranges from light to dark green. About 16 to 20 ribs run along its sides. Small, chin-like bumps sit between the areoles. Young areoles carry white felt. Fine spines spread across the stem and may curve or twist. Their shades include brown, red, white, and yellow. Longer central spines can point outwards or bend down.

Bright yellow, funnel-shaped flowers grow at the stem tip. One to five flowers may open together. Each spans about 0.16–0.26 feet (0.05–0.08 m). The flowers have red stigma lobes and some reddish petal tips. The RHS records spring flowers, while LLIFLE gives summer. Green fruits range from egg-shaped to round. Their thin walls split or break down when ripe. Each fruit can hold more than 100 seeds. The seeds are small, shiny, and black.

Grow this cactus in a house, conservatory, or greenhouse. The RHS recommends cactus compost with good drainage. Sandy soil with an acid or neutral pH suits it. Give it full sun or bright, filtered light under glass. Water moderately from mid-spring through late summer. During that period, give low-nitrogen feed every two months. Keep the compost nearly dry through the remaining months. Its RHS hardiness rating is H2. It tolerates cool conditions but cannot survive freezing.

No pruning is needed. Sow seed in spring or summer at 20°C. Watch for mealybugs, though the RHS reports few disease problems. Handle the plant with gloves and other protection against its spines. The RHS warning concerns these sharp spines, rather than confirmed poisoning. The supplied sources do not establish edible uses or pet safety.