A dive into the fascinating world of Madagascar's enchanting succulent Euphorbs

Madagascar is known for its rich biodiversity and is home to a variety of unique succulent plants, including several species of Euphorbia. Many succulent euphorbs in Madagascar are threatened by habitat loss, overgrazing, and collection for the horticultural trade.

Madagascar Euphorbs are part of the Euphorbia family, which is one of the largest and most diverse plant families in the world. The Euphorbia most people are familiar with is poinsettia, a popular ornamental plant that is native to Mexico and used as decoration during the holidays. I recently had lunch with an old friend who asked "What's up with the genus Euphorbia anyway? Isn't it too big?"  I replied YES! The genus is probably too large and all encompassing and should be subdivided. Euphorbia pulcherrima (Poinsettia) probably should not be in the same genus as Euphorbia obesa.  But I digress. Let's return to the subject at hand.

The most well known of Madagascar's succulent Euphorbs is Euphorbia milii, widely grown as an ornamental plant in many parts of the world. My mom had a giant one when I was growing up.

It is estimated that there are over 170 species of succulent euphorbias found in Madagascar. Obviously I can't cover them all here and instead will show a few that I have in my collection:

Euphorbia platyclada was one of the first succulents I purchased from a plant sale at UC Davis arboretum in the early 1990s, and its weirdness sparked my interest in collecting succulents. It's a plant I still cherish. E. platyclada does not have leaves in the traditional sense. Instead, it has flattened, stem-like branches that resemble sticks. These branches perform the photosynthetic function of leaves, allowing the plant to produce energy from sunlight. The lack of traditional leaves is a common feature of many succulent plants. E. platyclada is almost always in flower but the flowers are small and nondescript.  

It's easy to grow and the stems have a beautiful mottled pink-brown patina that changes hues with the seasons.

If people are interested I can list some for sale this year. I have made some potential polyploid forms that have larger stems and a more upright growth habit.  

Euphorbia decaryi is a small, compact plant with a thick, cylindrical stem that is covered in short, spine-like projections. 

Euphorbia capsaintemariensis has a somewhat similar look to decaryi but has smaller leaves, a bushier growth habit and forms a larger caudex ( a thickened bulbous or woody stem that found in some succulents). The plant below is one I have had for many years. The planter is a large carved piece of pumice that was birthday gift from a good friend.

Euphorbia nadine. I LOVE this plant!

It has gorgeous red and black patterned leaves and forms a thick underground stem.

I have several and was hoping to propagate and sell seedlings, but the plants are just too slow and fussy. I have tried them in different environments-the greenhouse, under lights in my francoisii growth room, but they seem to only be happy in an eastern facing windowsill that gets blasted with summer sun. They bloom in the late winter and spring and every year I try to cross them with my E. francoisii and every year it fails. I will try again this year.

Last but not least is Euphorbia francoisii. 

Euphorbia francoisii is related to E. decaryi and E. capsaintemariensis but features more colorful leaves. The plant above is one of the forms I have created and looks completely different from the original wild progenitors. 

Madagascar euphorbs make excellent houseplants. They are relatively easy to care for, but they do have some specific needs that should be met to ensure they thrive. Care instructions will vary slightly from species to species but here are some general care instructions:

Indoors vs. outdoors: These plants do better indoors for me. I have some in the greenhouse but they actually prefer to be in my home. They don't like temperature extremes.

Soil: Well draining soil is essential, I use a high pumice mix, but the mix I use for euphorbia is more rich in moisture retaining coir than the mix I use for Haworthia. 

Light: They do not require the high light levels that cactus and some other succulents need to thrive. They thrive in windowsills with bright light and one to two hours of direct sun. 

Watering: I water once every one to two weeks, less often during the winter. 

Temperature: Madagascar euphorbs are tender and do not like cold. In general they prefer warm temperatures and do not like temperature extremes. 

Pests: The usual succulent pests - mealybugs, scale, spider mites - can be a problem with Madagascar Euphorbs. They are especially susceptible to root mealies which require treatment with a systemic insecticide. You can read my blog on Mealies for more information about them. Madagascar euphorbs are also susceptible to powdery mildew if the conditions around them are too cold and humid. I use sprays of Neem oil, alcohol or hydrogen peroxide to control powdery mildew if it crops up.