Astrophytum Myriostigma | Rare And Unusual Cactus |

Astrophytum myriostigma is a famous spineless cactus. They belong to the family cactaceae family and to the genus Astrophytum. 

They have inherited the name called Astrophytum from the Greek language and it literally means the star plant. 

Astrophytum myriostigma grows in a star shape. Astrophytum myriostigma go by the common names called Bishop’s cap cactus, star cactus , Bishop’s Miter cactus and Bishop’s hat.

Astrophytum Myriostigma

Growing succulents and cactus is quite easy and Astrophytum myriostigma is no different to them. Astrophytum myriostigma are native plants to Northern and central Mexico and they usually grow in stony and calcareous soil in their natural habitats. 

When they grow in their natural habitats, they will grow at highly elevated places as 2500- 5000 feet above the sea levels.

From this article, I will be covering how you should look after them, the propagation methods and special care tips you need to practice  when growing them. 

Besides, I will be covering the common bugs and issues you may also come across when growing them. So, if you wish to learn further on these precious plants, this article would be useful for you.

How do I identify  Astrophytum myriostigma?

Astrophytum myriostigma carry an attractive foliage.

However, one of the prominent features of these plants is that they produce flowers which are yellow, and it would further stimulate the beauty of these plants. 

Astrophytum myriostigma flowers are daisy like and they will form right on top of the mature plants. The flowers would be about 2 inches in width.

Astrophytum myriostigma flowers will stay alive for about two days. However, they will keep flowering for months until they finish their flowering season. 

Astrophytum myriostigma flowers would be yellow. Besides they may carry a center in yellow. You could use this feature during spring or early summer to identify the Astrophytum myriostigma plants. 

Astrophytum myriostigma blooms have  a faint trailing scent as well. However only 5-6 years matured plants will produce flowers.

Astrophytum myriostigma stem would be either globular or cylindrical. They would be 60-100 cm in height. 

However, chances are that you may also spot them growing tall up to 150 cm too. Moreover, they would be about 10-20 cm in diameter when they grow to their fullest. 

The stem color would be bright green and they may carry  hairy  scales as well. It will give a characteristic   chalk white or a silvery gray look as well. 

Astrophytum myriostigma consists of fine roots and they are fibrous. Astrophytum myriostigma would consist of ribs of about 5 or less. However, as they grow, they will tend to increase up to eight. Those ribs would be vertical deep  and very broad.

See also  25 Snake Plant Varieties For Your Amazing Garden

Besides all the features mentioned, Astrophytum myriostigma have fruits which would be 2-2.5 cm in diameter. 

You could spot their fruits in greenish to tannish red in color. Further they may also carry overlapping scales with long wool too. Astrophytum myriostigma have seeds also in the fruits and they will be dark brown in color.

Growth rate

Astrophytum myriostigma are slow growers.. As aforesaid they would take about 5 years to produce flowers also.

One look care guide

Botanical NameAstrophytum myriostigma
Common NameBishop’s cap cactus
Star cactus
Bishop’s Miter cactus
Bishop’s hat
Plant Typecactus
Mature Size23-39 inches in height
Sun ExposureFull sunlight to partial shade
Soil TypeWell draining
Soil pH5.5-7
Bloom TimeSpring summer
Flower ColorYellow
Hardiness ZonesUSDA hardiness zones 10-11.
Native AreaMexico
Average price 10 USD
Astrophytum Myriostigma

How do you take care of  Astrophytum myriostigma?

Light Requirement 

Astrophytum myriostigma has strong demand in terms of sunlight requirements. Morning sunlight would work well with the plants. 

Partial shade during  the afternoon hours would work well with these plants too. If you have grown them as indoor plants for extended periods and wish to bring them outdoors, ensure that you slowly expose them for full sunlight as unless it would create sunburns in the plants.

Temperature and humidity

Astrophytum myriostigma are tolerant of warmer temperatures. When the temperature drops during winter ensure that you allow the plants to rest during winter.

Is it cold hardy?

Astrophytum myriostigma are half cold hardy plants.

USDA Hardiness Zone

Astrophytum myriostigma  are hardy in USDA hardiness zones 10-11.

Watering Requirement

Astrophytum myriostigma has very minimal water requirements. Hence you need to suspend watering them from October to March

You can start watering them sparingly from March and increase it slowly as the temperature rises. Ensure that Astrophytum myriostigma are tolerant of minimal water only. 

Refrain from  over watering  them. Further ensure that the soil mix is dry before you water them again. 

However, you can consider watering them slightly if you spot the plants becoming shriveled during winter. If there are lapses in how you water them, it will create root rot in the plants.

Soil Requirement Type / ph.

Astrophytum myriostigma could perform well If you grow them in a cactus soil mix.

Further you may also go ahead with a mixture of coarse sand, pumice and with potting soil at a ratio of 1:1:2. Further you may add a layer of sand on top of the soil layer too. 

See also  Astrophytum Myriostigma Quadricostatum (One Of It's Kind)

Avoid growing them in a soil mix which is rich in compost as it will make the plants elongate. It is critical that you grow them in a fast-draining soil mix as only then you can rely on the vigorous growth of the plants.

Pot size Potting and Repotting.

Astrophytum myriostigma have small roots. Hence go ahead with small pots when you grow them

Additionally ensure that it has one draining hole also in the bottom of the pot. Await until spring . to repot them.  

Furthermore, If you spot your plants have outgrown from the pot, you need to immediately report them.  You need to go ahead with a slightly larger pot when repotting.

Where to Plant

Astrophytum myriostigma are not cold hardy plants.

Hence if you are someone who lives in a place where the temperature gets colder than the 30 degrees Fahrenheit (-1.1 degrees Celsius ), you need to plant them in containers which you can easily move in and out from the home. 

However, when you bring them indoors, ensure that you grow them closer to grow lights. They would grow well if you fulfill the sunlight requirement.

Hence when you grow the Astrophytum myriostigma plants as indoor plants, a bright sunny windowsill would be the best place to locate them.

Fertilizer and time of year

Astrophytum myriostigma do have strong demands when it comes to fertilizers

Further when feeding, you need to go ahead with a liquid fertilizer which has a low component of Nitrogen once a month during summer.  

Suspend feeding them during their dormancy and if you end up overfeeding them it will result in feed burns of the plants.

Astrophytum Myriostigma


Astrophytum myriostigma produces flowers in yellow. Further they may carry orange centers as well. Their flowering season would be  spring or early summer. 

Further you can expect only the plants which are five to six years old to flower. These flowers contain a faint trailing scent too. Astrophytum myriostigma flowers will stay in bloom for two to three days.


Astrophytum myriostigma are winter dormant plants.


Astrophytum myriostigma are nontoxic plants.

Common bugs and illnesses

Astrophytum myriostigma may suffer from mealybugs, scales mainly. Having said that, they are resistant to pests’ attacks in general if you ensure that you look after them well

See also  Desert Agave | 16 Outrageous Care Facts Just For You |

If you keep them exposed for higher temperatures in winter, it will make them probe for these pests’ attacks. 

However, when they suffer from these attacks, you can remove them from the affected areas while using a toothpick and treat them with a piece of cotton dipped in alcohol.

Moreover, they may suffer from powdery mealworms as well. They would attack the cactus more often. These are suckers. 

You can  treat them with insecticidal soap. When you apply them ensure that you are adhering to the labeled instructions.

Stem rot is another issue which these plants may come across. It could mainly take place due to over moistening. 

When they get water in excess, they will become swollen. Further they will spread spores of pathogenic fungi as well. It will eventually result in the stem rot. However, if the stem rot is on a minor level, let it become dry.

Root rot is another issue which these plants may frequently suffer from. The faults you do in watering cause this condition. 

However, you can find out about this disease only when it is too late.  When the roots die, the stem will become yellow and become softer. 

It is important that you rectify this issue well in advance as only then it will allow you to save the plants. If it gets, chances are that you may even lose the plants. To treat them, best would be to first cut down on watering them and repot them afterwards in a fresh pot.

Special Care tips

Astrophytum myriostigma do not need any regular pruning as they can sustain on their own.


Astrophytum myriostigma plants would be great houseplants.

They will add so much grace to your  space and when they are in full blossom, it will be even more graceful to look at them. Even a fresher in gardening can start growing them due to the easy maintenance  they require.

How to propagate Astrophytum myriostigma.

The Seed propagation method is the best way to propagate the Astrophytum myriostigma plants.

Arrange a sandy well-draining soil mix and next place the  seeds in the soil. When you do this, ensure that the temperature is maintained around 78 degrees Fahrenheit.

Further keep them slightly moist. When they germinate and start to grow, you can grow them in individual pots. Ensure that you are using a soil mix which is described above.


Before winding this up, Astrophytum myriostigma plants are such a versatile attractive set of plants which would be quite grateful to have. 

You can start growing them even though you are a fresher. Their flower blossoming activity is yet another reason why you should have these precious plants. So, Happy gardening with Astrophytum myriostigma plants!

Credit to : Succulents Network
Read Next : 
My Baby Toes Dying, What Should I Do ?
Baby Toes Succulent Propagation | 4 Effective Methods |
Euphorbia Gorgonis | It Reminds Me ‘The Medusa Head’ |
About author

I’m Dr. Chamika, As a hobby love talking about plants and showing you that taking care of indoor plants. My website is knowledge I’ve learned over the years and continue to learn about growing succulents. If you’re a succulent lover, then you have come to the correct place.