About the genus
Just about every species of this large genus is good for cultivation.
The name Parodia is here used in its broad sense to include plants that can also be seen labelled in collections as Brasilicactus, Brasiliparodia, Eriocactus, Notocactus and Wigginsia. Many new species were discovered in the second half of the 20th century and these plants enjoyed a period of great popularity. Recently, they have fallen out of fashion but they are wonderful plants to cultivate, so they deserve a revival of interest.
In nature, they have an extensive distribution in Argentina, Bolivia, southern Brazil, Uruguay, Paraguay and even Colombia. Their habitats are diverse, ranging from grassland to rocky outcrops, gravelly slopes to vertical rock cliffs in forest. A conservative treatment would recognise around 70 species, a suitable number for the basis of a specialist collection.
Flowers are produced from the young areoles in the crown of the plant and are often large and showy. They can be yellow, orange, red, pink or purple and even green but never white.
How to grow them
Almost all are easy to grow and flower in cultivation. For the best results, the compost must be acidic, around pH6 is ideal. This can be achieved by using a mix which comprises equal parts by volume of ericaceous compost (such as used for rhododendrons), sterilised lime-free topsoil and 3mm lime-free grit (such as quartzite).
Watering in the growing season should aim to keep the soil moist and rain water should be used to avoid introducing any alkalinity that can be found in tap water. An occasional light watering on bright days in the resting period will help to stop root loss due to excess dryness. This is particularly appropriate for the smaller-growing species such as P. alacriportana, P. microsperma, P. rechensis, and P. tenuicylindrica.
Many species are tolerant of a partly shady location but good light is still needed for successful growth and flowering. There are a few Bolivian parodias (in the strict sense) which need full sunshine and more careful watering. Examples are P. aureicentra, P. commutans, P. maassii, P. ritteri and P. stuemeri.
Propagation is usually achieved by growing plants from seeds but a few make offsets which can be removed and often already have roots.
Parodia buiningii: A very distinct species with an unusual epidermis colour, often seen labelled as a Notocactus. One of the more challenging to grow well.
Parodia haselbergii: Very popular and spectacular species covered with dense white spines. The contrasting red flowers are very long-lasting for a cactus.
Parodia microsperma: Flowers easily when young, either red, orange or yellow. Sensitive to alkalinity and dryness so it needs a little rain water in winter.
Parodia scopa: Dense spination in various colours, columnar-growing, yellow flowers. Often called a Notocactus.
Parodia warasii: A larger-growing columnar plant with big shining yellow flowers. It is very easy to grow with lots of water in summer. Sometimes labelled as Eriocactus.
Parodia werneri: The purple flowers are an unusual colour for a cactus. There is also a yellow flowered form. It is often labelled as Notocactus uebelmannianus.
Text and photos: Graham Charles
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