Description
Astrophytum asterias ‘Super Kabuto’ with its inimitable fuzzy epidermis is actually the most popular cactus cultivar. It is easily distinguished from the normal Astrophytum asterias by the epidermis, that does not have simple dots, but a mosaic of extensive white spots that make the plant look intensely maculate. Many different beautiful forms of ‘Super Kabuto’, which differ for the diverse pattern of the spots are now available and it would be difficult to mention them all. Astrophytum asterias cv. Superkabuto Yellow Dots Type is a very nice cultivars that combines the shape of Astrophytum asterias cv. Superkabuto with a very peculiar colouring of the fuzzy spots, that are bright yellow in the new growth, but turning a more normal white colouring as they ages.
Roots: The underground body is fleshy, turnip-like, with fine diffuse roots.
Stem: Non-branched, much depressed, disc-shaped to low dome-shaped, grey-green to dull green (unless stressed), mature plants up to 7 cm tall, 5-16 cm broad, dotted with a mosaic of extensive white spots and V-shaped subtending each areole that make the plant look intensely maculate. Cultivated plants possess sometimes very dense and big hairy scales which in the “Yellow Dots Type” takes a bright yellow colouring in the new growth.
Ribs: The stem is typically divided by very narrow but distinct vertical grooves into 8 broad ribs. The ribs are very low, almost flat on top, forming triangular sections with no cross-grooves. The normal rib number eight is very stable in wild specimens, independent of the age of the plant, but in cultivation selected cultivars and hybrids can have from 4 to 13 ribs.
Areoles: Round, prominent, 3-12 mm in diameters, forming a line up to the centre of each rib, felted to hairy, white, creamy, dirty-yellow till straw-coloured, then grey. Normally 3 to 10 mm apart, but sometime very close one to each other in cultivated plants.
Spines: Not any.
Flowers: Apical, diurnal, radial, 3-5 cm long, 5-9 cm in diameter opening widely, yellow with orange/red throats. Ovary and tube very short, densely covered with thin, bristle-like, black tipped scales and with cobwebby wool in axils.
Blooming season: Spring to summer and each flower lasts for one or two days only, but the plant may flower at any time during the warmer months of the year if adequate water is provided.
Fruits: Oval to round, about 1,5-2 cm long, green, pinkish or greyish-red densely covered with spines and dull-white wool, becoming dry and finally breaking off at or near base (not opening above the base).
Seeds: Black or dark brown, glossy, bowl to helmet shaped about 2 mm long, 3 mm broad.
Origin and Habitat
Garden origin (Nursery produced cultivar). There are several forms mainly selected by Asian growers, particularly in Japan.
Cultivation and Propagation
Astrophytum asterias cv. supekabuto is a summer grower plant relatively easy to grow. It is sometime seen as a grafted plant but grows well on its own roots too. It is not too difficult in a greenhouse, although grows slowly.
Soil: Use mineral well permeable substratum with little organic matter (peat, humus), plants may become too elongated if compost is too rich.
Repotting: It needs to be repotted frequently. Eventually, as it becomes mature, it attain a maximum size of 8-10 cm (20) cm. However, old plants become senile and have a tendency to succumb to disease and a weak root system. At this stage, as is well known, they die suddenly. So, after they reach 10 cm in diameter grow them slowly, and adopt a new repotting period, using intervals of every 2 - 3 years. Use pot with good drainage.
Fertilization: It grows much faster with a low nitrogen content fertilizer in spring and summer. Potassium helps maintaining the plants compact and healthy.
Watering: Requires careful watering to keep plant compact. Water sparingly from March till October, the thin, fibrous roots suffer if there is humidity, therefore the plant should be watered only when the surrounding terrain is dry. Keep dry as soon as the temperature starts dropping in October and keep it perfectly dry in winter at temperatures from 5 to 15 degrees centigrade.
Be careful: The epidermis of Superkabuto is harder than in the normal asterias and cracks easily if plants are overwatered.
Hardiness: They need to be kept in a cool place during winter rest and are somewhat resistant to frost if kept on the dry side prior to, and during, cold weather (due to the altitude they are hardy to -5 C ° C, or less for short periods). It tends to rot in winter during the resting phase, if kept wet. In the rest period no high atmospheric humidity!!
Sun Exposure: It needs a good amount of light. Light shade to full sun, its colour tends to richer and darker when grown in light shade.
Uses: It is an excellent plant for container growing. It always looks good and stays small.
Pests & diseases: It may be attractive to a variety of insects, but plants in good condition should be nearly pest-free, particularly if they are grown in a mineral potting-mix, with good exposure and ventilation. Nonetheless, there are several pests to watch for:
- Red spiders: Red spiders may be effectively rubbed up by watering the infested plants from above.
- Mealy bugs: Mealy bugs occasionally develop aerial into the new growth among the wool with disfiguring results, but the worst types develop underground on the roots and are invisible except by their effects.
- Scales: Scales are rarely a problem.
- Rot: Rot is only a minor problem with cacti if the plants are watered and “aired” correctly. If they are not, fungicides won’t help all that much. To prevent rottenness it is also advisable to surround its root neck by very rough sand or grit, this help a fast water drainage.
Propagation: By seeds, remembering that seedlings dislike strong light and dry conditions and need to be repotted frequently. But plants are often grafted to accelerate growth as they would generally take at least a five years to reach maturity on their own, but the grafted plants are typical rather tall growing, compared with plants on their own roots that are usually more flat to the ground.
Remarks: This quite variable plant has been widely grown for years and is now available in several cultivated variety and several breeds do exist. The famous “Superkabuto” is only one of these and though maybe the most beautiful, but a lot of other forms are represented in many collections.
Bibliography
Major reference and further lectures
-
Hadley Nation “Super Kabuto and Rare Astrophytum: Limited Edition Collector’s Guide” Little Quin Publishing, 2007
-
Sato, T., “J.C.P Color Hand Book Series No. 2, Volume 1, Hand Book Asterias Family” page 1-65, Japan Cactus Planning Co. Press. 03/25/1973
-
Benadom, D., “Cacti & Succulents for the Amateur” in: Cact. Succ. Journ. (US), volume: 70 No. (6), page 314-315, 1998
-
Kleszewski, K. P., “Verein der Kakteenfreunde Mainz/Wiesb. u. Umgebung, OG, Astrophytum asterias (ZUCC.) LEM. Am Standort in Mexiko…und in Kultur” in: Kaktusblüte, volume: No., page 25-28, 1998
-
Kibayashi, A., “Cacti and succulents in Japan, part 1” in: Cact. Succ. Journ. (US), volume: 65 No. (3), page 126-127, 1993
-
Kobayashi, A., “Cacti and succulents in Japan, part 3” in: Cact. Succ. Journ. (US), volume: 68 No. (5), page 245-249, 1996
-
Sato, T., “Astrophytum asterias varieties” In : A Quarterly Cactus & Succulent Journal of Japan, volume: 1 No. (1), page 22-34, 1978
-
Sato, T., “Astrophytum asterias” in: Cactus & Succulent Journal of Japan, volume: 9 No. 7, page 10-14, 1995
10 ) Sato, T., “Astrophytum asterias” in: Cactus & Succulent Journal of Japan, No. 3, page 10-14, Japan Cactus Planning Co. Press, 1995
-
Sato, T., “Contest of Cactus & Succulent plant in Kyoto 1998” in: Cactus & Succulent Journal of Japan, No. 11, page 2-7, Japan Cactus Planning Co. Press, 1998
-
Sato, T., “Contest of Cactus & Succulent plant in Saitama 1998” in: Cactus & Succulent Journal of Japan, No. 12, page 2-4, Japan Cactus Planning Co. Press, 1998
-
Sato, T., Cactus & Succulent Journal of Japan, No. 6, page 2, 7, Japan Cactus Planning Co. Press, (unknown) 1999
-
Sato, T., Cactus & Succulent Journal of Japan, No. 7, page 9, 10, 15, Japan Cactus Planning Co. Press, (unknown) 1999
-
Sato, T., 1999 “The report of the grand meeting to celbrate the 20th anniversary of ‘KYOSENKAI’” in Cactus & Succulent Journal of Japan, No. 9, page 2-11, Japan Cactus Planning Co. Press,
-
Anderson, M., “Grafting succulents” in: Cact. Succ. Journ. (US), volume: 69 No. (1), page 17-25, 1997
