Notocactus Graessneri Description: Parodia haselbergii subsp. graessneri (a.k.a. Brasilicactus haselbergii, Notocactus haselbergii) is a medium- sized solitary, fast growing cactus closely resembling Parodia haselbergii, but has as many as 60 radial spines. The spines are pale to golden yellow, occasionally brownish or nearly all white, to 2 cm or more. The flowers are small yellowish green to almost truly green, while those of Parodia haselbergii are orange-red to bright red. These cacti are self-fertile, do not offset, and have a very short floral tube. They are among the earliest Notocacti to bloom in the spring. As with P. graessneri, the growing centre tends to be on one side of the stem.
Notocactus Graessneri Stem: Spherical flattened or spherical and depressed at the top, deep green, almost completely hidden by dense spines, up to 10 cm tall, 15 cm in diameter. The crown of the plant is usually set at an angle to prevent water-sitting.
Ribs: More than 30 (up to 60), low arranged in spirals.
Areoles: With a short yellowish-white wool, they are arranged geometrically.
Spines: It has as many as 60 pale yellow to golden yellow spines up to 25 mm long, of which the 5 or 6 centrals are thicker, soft and bristly. Occasionally the spines are brown or near white often with darker tips. The white-spined form may be confused with Parodia haselbergii when not in flower.
Flowers: Small yellowish green, up to 2,5 cm long and 2 cm wide and each can last one to three weeks. Petals semi-erect spreading and not closely surrounding the style, the stamens visible. Tube relatively long with clusters of bristles and some wool. It is self-sterile.
Blooming season: It flowers at the end of the winter or in early spring for a long period of time (It can last blooming to two months!). Will start flowering around 5 cm in diameter. Golden yellow or orange flowered varieties are also mentioned in cultivation.
Fruit: Spherical, about 2 cm.
Seeds: 1 by 0,5 mm, bell-shaped, widest at the hilum, reddish-brown.
Cultivation and Propagation: Parodia haselbergii subsp. graessneri is an easy to grow tropical cactus.
Growth rate: It is a relatively rapidly growing and easily flowering species that will make clumps given the best conditions.
Soils: It prefers a neutral to slightly acidic mineral-based potting mix with a good drainage.
Repotting: Use pot with good drainage.
Watering: It can support quite some water during the growing season, but do not overwater (Rot prone). Pot plants in winter are wet-sensitive and need to be kept dry (rots easily if soil is wet and cold) tend to lose their roots in winter. Best if watered with rain water.
Fertilization: Feed it once during the growing season with a fertilizer specifically formulated for cactus and succulents (poor in nitrogen), including all micro nutrients and trace elements diluted to ½ the strength recommended on the label. It thrives in poor soils and need a limited supplies of fertilizer to avoid the plants developing excess vegetation, which is easily attacked by fungal diseases.
Hardiness: Usually it is recommended to over-winter this plant in a bright and warm greenhouse with at least 8-10° C , but it has proved to tolerate temperatures as low as -5° C for short periods.
Exposition: Outside bright but partially filtered sunlight or afternoon shade, inside it needs bright light, and some direct sun. Subject to sunburn if exposed to direct sun for too long. Tends to bronze in strong light, which encourages flowering and heavy wool and spine production.