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Image of Astrophytum asterias

Maureen Gilmer



Botanical Name


Plant Common Name

Sand Dollar Cactus, Sea Urchin Cactus, Star Cactus, Star Peyote

Special Notice

This entry has yet to be reviewed and approved by L2G editors.

General Description

These tiny round hemispheres make exceptional windowsill cactus due to their unique markings and spinelessness. The species is native to thorn shrub vegetation of southern Texas and northern Mexico. It is often found in the filtered shade beneath shrubs, which act as nurse plants for protection from the brutally hot sun. This proves a tolerance for indoor conditions. Sadly, unscrupulous collectors have gathered so many old wild specimens that it is now listed as endangered in the U.S. Endangered Species Act. Beware of purchasing any that may appear to have been wild collected. All young plants seen in the nursery industry today are grown from seed harvested from cultivated parent stock.

Each plant is a perfect circle divided into eight identical segments like a pie or an orange cut in cross section. Each segment features centrally prominent fuzzy areoles from which nickel sized yellow flowers rise in spring. The olive green skin is covered with patterns of fine chalky scales. Handle this cactus with care since the scales can be rubbed off with handling and will not grow back.

This is the trickiest of all star cactus to grow due to its tendency for the root crown to rot out at the soil line. The reason is that the flat bottom of the cactus does not allow moisture to readily evaporate. When rotting, the top portion begins to wrinkle, which is mistaken for dehydration and often leads to yet another water application, which finishes them off. To avoid such risk, make the top inch of potting soil nothing but coarse sand or very fine gravel so that there is sufficient air penetration to dry out moist pockets that occur around the root crown. Very slow growth and small size is what makes this a stellar choice for small bonsai pots and other creative containers on porch, window sill or balcony.


  • AHS Heat Zone

    12 - 10

  • USDA Hardiness Zone

    13 - 15

  • Sunset Zone

    21, 22, 23, 24

  • Plant Type

    Cactus or Succulent

  • Bloom Time


Growing Conditions

  • Growth Rate

    Very Slow

  • Water Requirements

    Xeric/Desert, Drought Tolerant

  • Habit


  • Seasonal Interest

    Spring, Summer, Fall, Winter

Ornamental Features

  • Flower Color


  • Fruit Color


  • Flower Petal Number


  • Showy Fruit


  • Edible Fruit


Special Characteristics