Astrophytum asterias / 10 seeds (Sand Dollar Cactus, Star Peyote, Star Cactus)

Astrophytum asterias is a species of cactus native to Rio Grande Valley of Texas, United States and the states of Nuevo Leon and Tamaulipas in Mexico. Previously abundant in these areas, now Astrophytum asterias now occur only in a small part of Starr County, Texas and a few areas in Tamaulipas.

Only around 2000 specimens are believed to remain in the wild. It looks especially amazing because of small, round spineless, squat and disc-shaped body which is divided into 7 to 10 sections called ribs. In the center of each rib, there are round, cream-colored woolly areoles that are up to 3 to 12mm in diameter. Areoles may be separate at 10mm of distance from each other, or may be very close to each other in cultivated plants. It reaches to a height of 2.5 to 6 cm and diameter of 5 to 15 cm. Almost flat to the ground, Astrophytum asterias grows practically completely buried in its native habitat. It may have a spherical or columnar shape only in cultivation. Color is greenish-brown and is covered with white hairy scales (trichomes) which are sprinkled over the stem in irregular patterns, but sometimes arched around the areoles or on line. These scales are sometimes very dense and hairy in cultivated plants. But sometimes flakes are totally absent and pure green specimens are seen.

While the underground body (stem) of Astrophytum asterias is fleshy and turnip-like, roots are fine. Beautiful funnel-shaped flowers are produced on the top from March to June, and are yellow with red bases and very woolly outer parts. Fruits are green to pink and oval, and are covered with woolly hairs.  While blooming occurs from March to June (summer in its habitat), fruiting occurs from April to June. Primary pollinators are medium to large bees, with a species named Diadasia rinconis being the most effective.

The name of the genus Asterphytum comes from two Greek words, Aster meaning Star and Phyton meaning Plant, whereas the species name asterias derives from the Greek word “aster” which means “a star” an aster type plant and the Greek suffix “ias” means ‘like or resembling with or similar to’; thus it implies ‘star like (like an aster)’.

Since Astrophytum asterias has been labelled ‘endangered’, international trade of wild-collected specimens is prohibited, although illegal collection still threatens the future of this cactus and its fast reduced occurrence in the wild is attributed largely to over-collection and poaching. But it’s sometimes also harvested because of its resemblance with the closely related, coexisting peyote (Lophophora williamsii). Herbicides and urban developed are also considered contributing factors, although habitat destruction has been and still is the major cause of the decline of this species.

You can water Astrophytum asterias weekly during summer, if the weather is sunny enough. You can even add a little fertilizer to the water. This way, the plant will show a healthy, although slow, growth. This plant is frost hardy up to -4-degree C, although it loves warm temperatures above 70-degrees F all summer long with slightly cooler more temperate winter conditions. In extended period of 90-degrees or higher, increase watering to avoid stress. Growing Astrophytum asterias in high-humidity areas is not recommended as there is a risk of root rot and other diseases in prolonged humid conditions. Like many cacti, Astrophytum asterias do best with ‘soak and dry’ watering method. i.e. first you should give a good drenching and then let it dry out completely between waterings. You should give potted as well as outdoor Astrophytum asterias a deep water soak once a month during the growing season (June to September), making sure drainage is good and the plant roots don’t sit in water. You should stop watering your outdoor cacti altogether during periods of rain and winter. Astrophytum asterias is a winter-dormant species.

Astrophytum asterias is readily propagated from seed. Thus, most plants available in nurseries are seed-grown. Because of the popularity Astrophytum asterias among collectors, several cultivars are available. Among them, one cultivar, ‘Super Kabuto’ is particularly striking. This is a clonally propagated variety having large trichomes which congregate into dense spots. While the adult Astrophytum asterias is spineless, seedlings have some rudimentary spines within the initial weeks and months. Seedlings hate strong light and dry conditions, and should be repotted often. The plant reaches a maximum diameter of 8 to 10 cm; however, old plants tend to succumb to diseases and weak root system, and may die suddenly. Hence, once they reach a diameter of 10 cm, grow it slowly and adopt a new repotting period, with intervals of 2-3 years. Also, grow them under drier conditions or with stronger sunlight.

Plants are usually grafted to speed up growth since this plant generally take at least 5 years to reach maturity on their own. However, grafted plants re usually tall-growing, compared to plants growing on their own roots that are typically more flat to the ground.