Notocactus ottonis var. Paraguayensis


Notocactus ottonis
Notocactus ottonis var. globularis
Notocactus ottonis subsp. horstii
Notocactus ottonis var. janousekianus
Notocactus spegazzinii
Notocactus spegazzinii var. horstii
Cactus ottonis
Echinocactus amambayensis
Echinocactus araneolarius
Echinocactus arechavaletae
Echinocactus ottonis
Echinocactus ottonis var. paraguayensis
Malacocarpus ottonis
Melocactus tenuispinus


N. ottonis is native to Argentina Northeast, Brazil South, Paraguay and Uruguay.


N. ottonis is a cactus belonging to the Cactaceae botanical family. The plant has a short, spherical, globose stem, dark green in color but during winter dormancy it can get purple. The stem is arranged in 8-9 ribs divided by furrows. Each rib bears along the edge a row of short spines inserted on areoles. Spines are light brown to reddish, curved and tipped, 2 cm long. The cactus reaches 15 cm in diameter and 20 cm in height and at the top the stem is flattened. Blooming occurs throughout the summer and showy, wide, yellow flowers appear at the apex of the plant. Flowers are bright yellow with slight reddish stripes. Usually the plant grows solitary but sometimes it offsets and form a cluster.


This is a rare plant, easy to cultivate. The best sun-exposure is shade light, and the plant does not like temperatures below 8 °C so it needs to be placed indoors. The soil should be mixed with pumice, clay and loam to allow the drainage and prevent the root rot, the plant is prone to it indeed. Remember to use perforating pot to drain excess water. Watering can be done regularly from March to November: during the vegetative period you can water the plant (every 7 days), checking that the soil is completely dry before watering again; in winter you should stop the watering to allow to the plant to enter dormancy. If you want a faster and lush growth you can fertilize the plant once a month during the growing season with the specifics fertilizers for cacti; stop fertilizing throughout the winter. If the pot starts to be too small for the plant you can repot the plant in a pot 2 cm wider. Repotting should be done early in the growing season with fresh new potting soil. Be careful to red spiders and mealy bugs.


Propagation can be done by seed or by cutting. By seed is very simple to propagate the plant, it is enough to sow the seed in a sandy loam soil and keep it with high level of humidity; temperatures of germination are between 20 and 28 °C. By cutting you can use the offsets during the spring. Cut an offset and then let it dry; after a few days the cut surface will dry and a callus will form, then place the cutting in a mixture of sand, soil and pumice. To increase success of propagation you can cut two or more offsets at the same time. For cuttings is recommended temperatures around 20 °


Its name reflects its geographical area of distribution, that is further south than the one of many other cacti, which usually come from central part of the Americas. In fact, the Greek word ‘nòtos’ means southern. The name Ottonis comes from the German botanist Christoph Friedrich Otto.

Official Web Site:

Italian Blog:

Read our advice

Recent Posts

Start typing and press Enter to search