Parodia ottonis
| Light | Bright light with some protection from the harshest summer sun |
|---|---|
| Water | Regularly in growth once the soil dries; keep dry and cool in winter |
| Soil | Fast-draining but slightly humus-rich mineral mix (see Soil and potting mix) |
| Temperature | Keep above freezing; broadly USDA zones 9–11 |
| Propagation | Offsets, seed |
| Toxicity | Non-toxic to cats and dogs |
Parodia ottonis is a small, clustering South American cactus with a low, ribbed green body and strikingly large, glossy yellow flowers. Once widely known under the name Notocactus ottonis, it is one of the easiest members of the old Notocactus group to grow and flower, and a frequent recommendation for beginners. It offsets freely to form neat clumps and blooms generously even as a young plant.
Description
Parodia ottonis forms a flattened to shortly globular stem, up to around ten centimetres across, that clusters from the base to build up loose mounds over time. The body is a fresh mid-green and carries relatively few ribs — often around ten — which are broad, rounded and sometimes slightly notched. Each areole bears a modest spread of fine, pale to brownish radial spines and a few longer, darker central spines; the spination is soft-looking rather than fierce.
The flowers are the plant's great attraction: large for the size of the body, borne at or near the crown, and opening a bright, satiny yellow with a red-tinged stigma at the centre. They appear over spring and summer and open in sunshine over several days. Fruits are small and the seeds fine and dust-like.
The species is variable across its range, and many forms and old names have been folded into it. Growers may encounter plants labelled with a range of varietal or subspecific tags, most of which represent minor differences in body shape, rib count or spine colour.
Distribution and habitat
Parodia ottonis is native to subtropical South America, ranging across southern Brazil, Uruguay, Paraguay and northeastern Argentina. It typically grows in grassland and open, rocky ground, often nestled among grasses and low vegetation that give it light shade and a little extra moisture compared with the harsher desert habitats of many cacti.
Because it comes from summer-rainfall grassland rather than true desert, it appreciates more regular watering in growth than a typical arid-zone cactus, while still needing sharp drainage at the root.
Cultivation
This is a forgiving, quick-growing species and an excellent first Parodia. Grow it in a free-draining mineral mix that can hold a little humus, in bright light with some shielding from the most intense midsummer sun to keep the body a good colour. Water freely once the mix has dried during the growing season, then reduce sharply and keep the plant dry and cool over winter — a dry winter rest both prevents rot and encourages the following season's flush of flowers.
The species is more tolerant of moisture than many cacti, but standing wet, cold and airless is still the main way to lose a plant. See Watering and Repotting for general technique. As clumps fill their pots they can be potted on or divided.
Propagation
Parodia ottonis is easily propagated from the offsets it produces so readily: detach a well-rooted or firm pup, let any cut surface callus, and pot it into the same gritty mix (see Propagation — offsets and Propagation — cuttings). It also grows readily from seed, which germinates freely on a warm, humid mineral surface — the standard method for producing large batches and for maintaining the variation within the species (see Propagation — seed).
Common problems
- Rot — from cold, wet conditions or a poorly draining mix, especially over winter; the base softens and discolours.
- Etiolation — too little light makes the body stretch upward and pale, losing its low, tidy form.
- Pests — mealybugs (white fluff in the areoles and among the roots) and red spider mites (fine webbing, bronzed skin) are the usual offenders; see Pests and diseases.
See also
- Parodia — the genus overview
- Soil and potting mix · Watering · Propagation — offsets · Propagation — seed · Repotting