Notocactus concinnus v. gerbalitoensis in 6 Inch Live Cactus
Origin and Habitat: Yerbalito, Cerro Largo, Uruguay.
Habit: It is small cactus species forming a flattened and many-ribbed sphere.
Stem: Simple, broadly globular or somewhat depressed at apex, eventually longer in age, about 3-10 cm tall, and 4-10 cm across, light or dark glossy green, ribbed and warty at the top.
Ribs: about 16 to 20, with somewhat conspicuous chin-like tubercles between the areoles
Areoles: Young areoles white-felted.
Spines: 10 to 12, spreading, setaceous, hair-like to bristle-like, some more or less curved to twisted, brown, reddish or partly whitish to yellowish often poorly differentiated as centrals and radials.
Radial spines: 9 to 25, about 5 to 7 mm long.
Central spines: 1-4(-6), one much longer (1-2,5cm ), spreading or turned downward.
Flowers: 1-5 produced together at the apex, bright yellow, funnel-shaped, large, about 5 to 8 cm across. Outer perianth-segments narrow, acute, reddish, inner perianth-segments oblong, yellow almost transparent, except the reddish tips, acute. Stigma-lobes scarlet. Scales on the ovary hairy in their axils. Perianth-tube slender.
Blooming season: Summer.
Fruit: Green ovoid to globular approx. 1,5 cm cm long, thin-walled, splitting or disintegrating at maturity with more than 100 seeds per fruit.
Seed: 0,8-1 mm, bell-shaped broadest at the hilum, somewhat, tuberculate, shiny and black.
Cultivation and Propagation: It is relatively easy to grow on its own roots.
Soil: Grow it in an open sandy-gritty cactus compost.
Pots: It needs a relatively shallow pot to accommodate its fibrous roots and provide very good drainage. It may stay in the same pot for many years.
Watering: Water in moderation, it prefer a completely dry place during winter. Mature individuals easily rot and die especially after planting so be extremely cautious with watering. Keep dry in winter or when night temperatures remain below 50° F. Water it less than average if in bigger pots.
Special need: Provide very good ventilation. Nearly all problems occur as a result of overwatering and poor ventilation, especially when weather conditions are dull and cool or very humid.
Fertilization: Feed them once during the growing season with a fertilizer specifically formulated for cactus and succulents (high potash fertilizer with a dilute low nitrogen), including all micro nutrients and trace elements diluted to ½ the strength recommended on the label. They thrive in poor soils and need a limited supplies of fertilizer to avoid the plants developing excess vegetation, which is easily attacked by fungal diseases.
Exposure: It will do its best with lots of sun and become stressed with inadequate light which could result in poor growth and unnatural shape.
Hardiness: It likes warmth (recommended minimum winter temperature 41° F) however plants kept perfectly dry can can survive low temperatures, approx. 23°, but for safe cultivation it is best to avoid freezing temperatures.
Use: This is a good pot plant suited for a non heated green house. It can be also cultivated outdoors in raised beds, terraces if sheltered from winter rain. This cactus continues to be, a particular prize among collectors
Propagation: Seeds. The seeds can be sown in pots of fine, well-drained sandy soil, any time during the spring when temperatures are warm. Cover the seeds with a fine layer of grit and water from below with a fungicide to prevent damping off. For 1-2 weeks cover the pots with a sheet of glass/clear plastic to keep the humidity levels high. Remove the glass and replace it with light shade-cloth and mist once or twice a day for the next two weeks after which most seeds should have germinated. From then on misting can be reduced to every second and then every third day as the little plants grow.