If you are into succulents and thorny plants, you might rank euphorbias and cactus on the top of your list. But there are not many people who can clearly tell the difference between the two. This confusion gets even worse when euphorbias are sold as cactus in nurseries.
It might be difficult to visually differentiate between euphorbia and cactus plants, but those who are well-read might be able to see the distinction. Here is everything that you need to know to be able to distinguish between euphorbias and cactus…
Euphorbias VS Cactus
The reason why euphorbias and cactus happen to look very similar is due to convergent evolution. The cacti and euphorbias grow in very similar environmental conditions. Basically, their reaction to the climatic conditions was similar.
This causes a similar evolutionary development, causing striking resemblance without any significant ancestral connection. The Peruvian Apple cactus, for instance, is very similar in appearance to the Candelabra tree. Tracing the evolution of the two plants, you can see that the former evolved in the South American region while the latter evolved in the South African region.
Because of convergent evolution, the two plants appear the way they do today.
Apart from that, the cacti seemed to have evolved in the new world. They are found in the areas of central, north, south of America, and in few regions of the Caribbean. Succulents like euphorbias seemed to have evolved in the old world. They were found in the regions of Africa, Madagascar, and some dried lands of Asia.
The wild-type variants still see an abundance in their native lands. Few like Opuntia have escaped the wild habitat and gained weed status in foreign lands.
If you are not aware of the characteristic traits of both euphorbias and cacti, you might not be able to set them apart. Here are a few noticeable differences that you can be on a look for…
Types of Thorns
The thorns are a type of modified stems in these plants. Euphorbias are known to bear single or paired thorns. The thorns are very thick, and they are not a separate entity, rather a part of the stem. This means, if you try removing the thorn, you can only do so by wounding the plant and no way else.
Cactus, on the other hand, have spines, which are modified leaves. For a cactus, these spines grow in circles; however, that might not be the only case. Whatever the shape and structure maybe, the cactus spines always grow out of the areolas present on the stem. You can remove these spines easily without damaging the stem.
This visual distinction tip might not be fruitful for cacti and euphorbias that grow without spines and thorns, respectively.
Presence of Areoles
Areoles are cushion-like dots present on the stem of the plant. These are the spots from where other plant parts like spines, stems, and flowers grow. These areolar are a feature unique to cactus and not euphorbias. Areoles are present in all the cactus, without fail.
On a closer examination of the stem, if you are unable to spot any areoles, you can comfortably conclude that it is not a cactus. This is one of the most convenient and easy ways of distinguishing the two apart.
Euphorbias are known for producing milky sap on wounding. The nature of this sap is latex-like, which is sticky and toxic in nature; if it comes in contact with the skin, it can cause irritation and itching. The color of this sap is always white, except for E. abdelkuri that has a yellow sap.
In the case of the cactus, the sap is clear in color. The nature of the sap is not toxic, and hence it will not cause any irritation to the skin. There are a few cactus-like Mammillaria that have a white sap, but that is a rare scenario.
Cactus are known for blooming very vibrant and aesthetically appealing flowers. A cactus flower has all the basic flower parts like petals, stamen, etc. A cactus flower will grow out of an areolar always.
The flowers of euphorbias are small and yellow in color. They don’t have any petals and are very insignificant to the entire plant’s appeal. Some species also display colorful bracts, which are modified leaves that give the appearance of a flower. These flowers don’t grow out of areoles as areoles are not present on euphorbias.
Almost all adult cacti are leafless. There are a few exceptions, like Opuntia and Pereskia. But Otherwise, as the plant grows, it loses its leaves. In the case of euphorbias, even though the stem is succulent, it still bears leaves on it.
Genus and species
The euphorbias do not make an elaborate family of a different genus. In fact, they are a single genus in the family Euphorbiaceae. These plants are popularly known as spurges. You can find about 2000 different species in this genus, some of which are regularly seen as ornamentals at home.
Cacti are from an entire family, known as Cactaceae. There are around 175 genera in this family that harbor 2000 species. These include the popular ones like Opuntia, Echinocactus, Mammillaria, and Cereus.
It is very clear from the above-mentioned distinctive traits that euphorbias as cactus are not the same. You can very well distinguish the two with a close examination and thorough understanding.
Check the stem for areoles, compare the flowers, look out for thorns or spines. If you are able to draw a comparison about a few basic traits, you will be able to set the two apart.