The spurge family includes the enormous and diversified genus of flowering plants known as Euphorbia, sometimes known as spurge (Euphorbiaceae). In common English, the term “Euphorbia” is occasionally used to refer to all members of the family Euphorbiaceae as a whole (in honor of the original genus). [2] Some euphorbias, like poinsettias around Christmas, are commonly sold commercially. Some, like the crown of thorns plant, are frequently grown as ornamentals or are collected and highly valued for the aesthetic appeal of their distinctive floral structures (Euphorbia milii). Because euphorbias from Southern Africa and Madagascar’s deserts have developed morphological traits and shapes resembling cacti from North and South America, they are frequently mistakenly referred to as cacti. [3] Because they can withstand heat and drought and have attractive or striking overall forms, some plants are employed as ornamentals in landscaping. [4] [5]
The euphorbia genus includes small annual plants and enormous, long-lived trees.
The genus is one of the largest genera of flowering plants, with over[4] or over 2,000 members[6].
[7]
Along with Rumex and Senecio, it also possesses one of the widest ranges of chromosomal counts.
[7]The type species for the genus Euphorbia is Euphorbia antiquorum.
[9] Carl Linnaeus published the first description of it in Species Plantarum in 1753.
The plants all have strange and distinctive floral structures in addition to a deadly, milky, white, latex-like sap.
[4] The genus can be characterized by the traits of the DNA sequences of its members or by the morphology of the flower heads. The flower head appears to be a single flower when seen as a whole (a pseudanthium). It has a special type of bloom, called a cyathium, in which each flower in the head is stripped down to the minimal minimum required for sexual reproduction. [4] Each flower is either male or female, with the male flowers consisting only of the stamen and the female flowers solely of the pistil. [4] These flowers lack petals, sepals, and other components that are common to flowers in other plant species. [4] Supporting structures for the flower head and other structures below have evolved to draw pollinators through nectar as well as through patterns and colors that mimic the function of petals and other flower components in other flowers. It is the only plant genus that possesses all three types of photosynthesis—CAM, C3, and C4—all at once. [4]
There are a few key differences which I will break down:
Cacti are only indigenous to the New World, with the exception of the Rhipsalis baccifera. There are no cacti in Europe, Russia, Australia, nor in Africa or Asia (except for that one species of Rhipsalis). On the other hand, euphorbia are native to many regions of the world, although those from Africa and India are the most cactus-like.
Both cacti and euphorbias have prickles, however the prickles on each species are unique. All cacti have areoles, which are structures that serve as the source of the spines, which are modified leaves. The most common thorns on euphorbias are modified stems that are typically seen in pairs. Areoles do not exist in euphorbias.
Cacti and succulent Euphorbias both retain water for dry spells, but latex, a hazardous sap, is present in all Euphorbias. It is most likely a Euphorbia if you cut open a succulent and it weeps this white fluid.
Cacti and Euphorbias both produce flowers, however the blossoms are typically extremely dissimilar. Euphorbia blooms are often subtle, whereas cactus blossoms are frequently spectacularly colorful and striking. Flowers from euphorbia are frequently a light greenish-yellow tint. However, some Euphorbias, such as Euphorbia milii, have vivid flowers (Crown of Thorns).
So there you have it—in a nutshell, the similarities and differences between cacti and euphorbias. Next time you see a spiny succulent, you’ll be able to identify it as a cactus, a Euphorbia, or something else by taking a closer look.
Is a Euphorbia a succulent or a cactus?
The plant genus Euphorbia (Euphorbia spp.) contains more than 2,000 species. Around 1,200 of them are succulents, some of which have odd shapes and broad, mushy leaves, while others remarkably resemble cactus and have spines. The genus’ plants are frequently referred to as spurge or euphorbia by growers.
With repeated additions and deletions of species and subgenera, Euphorbia is a somewhat ambiguous genus. The genus contains species that are annual, perennial, and biennial. There are species of herbaceous plants, woody shrubs, as well as deciduous and evergreen trees and shrubs. The presence of a milky white sap in the plants is the defining trait among the species.
Most of the euphorbia species utilized for landscaping or as indoor plants are succulents with interesting forms and foliage, but a handful are also prized for their blooms. The poinsettia is one of the most well-known euphorbia species that is not a succulent.
The majority of euphorbias flower in the spring or summer and hibernate over the winter. Most species should be planted in the spring, when the risk of frost has gone, however houseplants can usually be started at any time. The growth rates of the species range from slowly to rather swiftly.
Euphorbia is poisonous to dogs, cats, and humans in all forms. Each plant species has a different amount of toxicity.
Why is a plant called a Euphorbia?
A genus of flowering plants in the spurge family is called Euphorbia (Euphorbiaceae). One of the biggest genera of flowering plants, Euphorbia contains approximately 2,000 different species, from diminutive annuals to enormous, long-lived perennial trees to deciduous shrubs. Some of the most recognizable euphorbias are poinsettia plants.
Plants native to Euphorbia are tough, hardy, and simple to cultivate in a variety of hardiness zones. Euphorbia plants are wonderful complements to flower beds and rock gardens because of their colorful leaves and distinctive flower structures called cyathiums. As long as they receive the proper amount of light, euphorbias thrive as both indoor and outdoor plants. The majority of them hibernate during the winter and bloom in the late spring and early summer.
Is euphorbia toxic to humans?
The milky secretion of the Euphorbia plant, sometimes known as latex, is extremely poisonous and irritating to the skin and eyes. This study provides an illustration of the range of ocular inflammation brought on by unintentional ingestion of Euphorbia plant latex. Three patients came in with recently developed accidental ocular exposure to milky sap of a Euphorbia species. In all cases, there was a significant burning sensation along with vision blur. Visual acuity decreased to counting fingers from 20/60. Clinical findings ranged from anterior uveitis to secondary increased intraocular pressure, mild to severe corneal edema, epithelial defects, and keratoconjunctivitis. With active supportive treatment, all symptoms and indicators disappeared after 10 to 14 days. When handling euphorbia plants, wear safety goggles. Asking the patient to bring a sample of the plant for identification is usually advisable.
Trees, succulents, and herbaceous plants all belong to the Euphorbiaceae genus.
[1] There are numerous kinds of Euphorbia that can be found growing in the wild or in gardens or homes as cultivated examples. The milky sap or latex is poisonous and can cause severe skin and eye problems. From moderate conjunctivitis to severe kerato-uveitis, ocular toxic response can vary [2]. There are a few case reports of people losing their sight permanently as a result of accidentally putting Euphorbia sap in their eyes. [24] Corneal involvement typically proceeds in a predictable order, with edema getting worse and epithelial sloughing on the second day. [3,5] Some species are thought to be more poisonous than others. [6] The inflammation usually goes away without leaving any aftereffects when it is promptly treated and carefully maintained. Here, we show three instances of ocular toxicity brought on by three distinct Euphorbia species: E. trigona (African milk tree), E. neriifolia (Indian spurge tree), and E. milii (Crown-of-thorns houseplant).
Do euphorbia plants contain thorns or spines?
How do you distinguish a cactus from a spiky euphorbia? Consider these essential details: the kind of spines, flowers, and leaves (or lack thereof).
I recently learned how to distinguish a spiny euphorbia from a cactus at a look when creating the new Euphorbia page for my website.
You can break a stem, and if milky sap drips from it, the plant is a euphorbia, whether it’s a succulent tree, spurge, or poinsettia. Yet, hey! You are no longer required. Take a look at the distinctions here, then test yourself on my YouTube channel. You’ll be thrilled with your newfound knowledge, I guarantee it!
Left: A cactus with spines, areoles, a pink blossom, and a fruit with seeds. The euphorbia at right has tiny, yellow flowers, some of which have developed into pods.
Euphorbia or Cactus? Check the flowers and fruit
In comparison to the plant, euphorbia blossoms are small. They are typically yellow, but they can also be light green, cream, pink, or red. The bracts that encircle genuine flowers are what appear to be petals.
The waxy, longer-lasting bracts have five rounded petals and resemble forget-me-nots.
The fruit that follows them is seed-filled and inedible; it may be knobby, spherical, or pumpkin-shaped.
Contrarily, the flowers of cacti typically have a spectacular, vibrant color, and a brief lifespan (a day or so). Flowers with delicate, satiny petals that resemble daisies or water lilies are created.
Cactus blooms produce an ovoid fruit that, in some species, is edible. The flesh is covered in tiny black seeds.
A defining characteristic of cacti is that spines emerge from areoles (bumps or tissue) that are different from the skin of the plant. Cactus spines also tend to be needlelike. Although not all cacti have spines (visible ones at least), all cacti have areoles.
Similar to rose thorns in texture, euphorbia spines frequently take the shape of a V, evoking images of bovine horns or a snail’s head. (Remember that many succulent euphorbias are thornless.)
Some species of Euphorbia have stems that support bracts that become dry and stick to the plant. Although these “peduncles” resemble spines, they are not sharp and are simple to break off.
Euphorbia or Cactus? Look for leaves
The crimson leaves of Euphorbia trigona ‘Rubra’ (left) are fringed. Right-facing cholla has spines for leaves.
Unexpectedly, euphorbias with spiky, cactus-like growths generate leaves. If you don’t see any, it’s because they usually aren’t significant and disappear seasonally in most species.
Cacti technically have “modified leaves” that have spines. Cacti stems can also resemble leaves. However, cacti don’t have leafy leaves like euphorbias do.
In addition, succulent euphorbias are native to the Old World, mostly Africa, while cacti are native to the Americas. These plants have become naturalized over the past few centuries in warm, arid areas all over the world thanks to collectors. However, someone in Hollywood didn’t do their homework if you’re watching a movie set thousands of years in the past and Jesus or Alexander the Great are seen walking past a cactus.
How should euphorbia be grown?
In general, euphorbias need a sunny location and rich, well-drained soil. Light types, meanwhile, can tolerate some shade and do well as ground cover around shrubs and trees.
How to plant euphorbias
Dig a deep hole when planting euphorbias that have been cultivated in pots and fill it with compost or leaf mould. Euphorbia should be planted firmly, then it should be watered well and mulched to keep moisture in and weeds out.
Here, Monty Don proposes two exceptional euphorbia species and provides planting instructions. Additionally, he offers advice on how to grow euphorbias from cuttings.
How to care for euphorbias
As long as the growing environment is favorable, euphorbias don’t need feeding or special care. After the blooms have faded, blooming stems should be pruned. However, gloves must always be used when working with euphorbias because their milky sap is hazardous if consumed and irritates the skin and eyes.
How to propagate euphorbias
Euphorbias can be grown by taking springtime cuttings. Wear gloves to protect your hands from the sap.
By collecting cuttings of Euphorbia characias subsp. wulfenii in the spring, you can learn how simple and gratifying euphorbia propagation is. Monty Don offers advice on how to maintain the cuttings’ viability, plant them, and shield your hands from the irritating sap:
Euphorbia grows annually or perennially.
Euphorbias are resilient, trouble-free perennial plants that are simple to grow. Euphorbias are well known for their distinctive flowers and brilliantly colored leaves, and they make wonderful additions to borders, rock gardens, meadows, and more.
Does euphorbia grow indoors?
Have a space in your home that receives a lot of light and begs for a plant? With the right care and attention, columnar euphorbia, which are intricate, sculptural succulents, will thrive inside. Continue reading for information on growing euphorbia as indoor plants as well as other fascinating facts about this beautiful plant. So come choose your favorite euphorbia at Flora Grubb Gardens, our store in San Francisco!
Let’s first address the biggest issue in the room: euphorbia are not cactus!
Despite having a similar appearance, cactus and columnar euphorbia are separate plants. You may observe the cactus’ rigid, upright trunk and arms if you look at a Saguaro. It grows in the desert and has spikes to protect itself from predators. Then take a look at a candelabra tree, which is a kind of euphorbia and has arms that are spiky for defense. In the desert, candelabra trees can also be found. What makes a difference, then? Contrary to popular belief, there are no cacti outside of the “New World.” Surely Africa has cacti, right? True, there are no cacti in Africa.
Understanding convergent evolution, which is described as “the process by which creatures that are not closely related independently evolve identical features as a result of needing to adapt to comparable habitats or ecological niches,” is necessary to reconcile this finding. In summary, because they were compelled to evolve in the same manner and under comparable circumstances, cactus and euphorbia are almost identical. Because this is an effective method for storing water, they are columnar. Spikes are used to protect that water. Despite having a similar appearance, they are totally unrelated despite having diverged over vast distances.
How do we tell the difference, then? The key differentiator is the flowers. Cactus blossoms are enormous, delicate, and frequently vividly colored. They are frequently pollinated by birds or bats. Fly pollination is common for euphorbia blooms, which are tiny, often green, and somewhat unimpressive. Whereas at first glance the spikes appear to be similar, closer examination reveals that euphorbia has thorns while cactus has spines (a modified leaf) (a modified stem). The majority of euphorbia have a toxic latex sap to aid in their defense, which is another distinct feature.
Columnar Euphorbia thrive well indoors when planted in a cactus mix that drains quickly. Here are some tips for taking care of them at home:
Euphorbias are warm-blooded plants, therefore south or west-facing windows inside—where the plant receives four or more hours of direct sunlight daily—are ideal, though they can also grow in extremely intense indirect light. If placed within 18 inches of a window, they could burn because their skin is more sensitive than cactus. To avoid this, arrange them so that they are angled toward the window. Make sure the plant has adequate drainage and is kept as warm as you can if you are growing it in bright indirect light.
Since these plants grow throughout the summer, water should be progressively increased through late spring and into the season when they can experience dryness without becoming completely parched. This indicates that the soil does not feel damp or chalky or cracked throughout the entire container. During this time, don’t leave them to sit about completely dry; shriveling is a sign that they haven’t received enough water. Although fertilizer is typically not necessary, you can use an all-purpose fertilizer in the summer at 1/4 strength.
During the fall, water should be gradually reduced. Euphorbia naturally receive relatively little winter precipitation. They should become completely dry between waterings over the winter. Make sure to let your euphorbia stand in a saucer of water until it has completely absorbed the water because it can be difficult to rehydrate a completely dry plant (as it is like a dry sponge, where water will just run off). Until there is standing water in the saucer that isn’t being absorbed, keep adding water and letting the plant sucking it out. The surplus water can then be emptied out of the saucer or removed by placing a towel, sponge, or turkey baster within the saucer to absorb it. Never leave columnar euphorbia submerged for longer than 12 hours.
Brown spots are the most typical problem with these columnar euphorbia. They may be corking if they are light brown and hard like a scab, which is the normal process of a plant aging. Consider corking as a tree’s smooth, green bark turning woody over time. Relax, this is very normal.
However, rot is present if the brown spots are deeper and mushy. The plant needs to have the rot surgically removed since it will spread and kill it. The more likely it is that you can rescue your plant, the earlier you catch rot. Three situations are possible here:
Dig down to healthy, vigorous tissue to treat a small area of rot, then let the plant repair by developing a scab.
You must remove the top, clear the rot from the top and bottom back to healthy, lively tissue, and then re-root the top if it has ringed the column halfway up. Replant the top in extremely fast-draining soil (half pumice or lava rock and half cactus mix) and set it in a warm, sunny location out of direct sunlight after allowing it to scab over for two to three weeks. If you have it, rooting hormone is also helpful for this. For re-rooting, cement or tile flooring work well because they carry heat to the plant; but, if you have a heat mat, you can use that as well. Set it to 72 degrees Fahrenheit. In this case, the top of the plant will produce a new plant, and the bottom plant will continue to develop and produce new heads. (You would also propagate the plant in this manner, typically in the late spring when it is actively growing.)
If the column’s base begins to deteriorate and spiral around it, you should discard the bottom and propagate the top. You may recall that we mentioned the plant’s latex sap is poisonous. Use gloves and avoid getting sap in your eyes while doing this because it is a serious skin and eye irritant.
Other typical issues with euphorbia planted indoors typically result from the plants being grown in chilly environments with little sunlight. Summertime underwatering of plants causes problems, but even a small amount of wintertime overwatering can be disastrous. Another typical error is to not water until the soil is completely saturated.
Euphorbia leucodendron and Euphorbia tirucalli ‘Sticks on Fire’ (also known as pencil cactus), two non-columnar euphorbias with lovely forking shapes that resemble aquatic flora almost as much as possible, may both be grown indoors. These require a lot of light to develop as houseplants and can even grow in bright, direct sunlight beside a window, just like the columnar euphorbia. (Not a good option for houses with pets due to the previously mentioned toxic sap!)
These incredible plants may, of course, also be cultivated outside in a temperate region like the Bay Area, even flourishing in the foggy streets of San Francisco. These euphorbia prefer a warm, protected location with plenty of sunlight and good drainage. They enjoy being next to radiant south- or west-facing walls or fences as well as slopes where water can drain off. Since they are summer growers, they will require more water during this dry period. However, if you want to fertilize, use an all-purpose fertilizer sprayed at 1/4 strength as they are typically not hungry. They frequently fail in clay soil, partial sunlight, or areas that receive an excessive amount of winter precipitation (in addition to our natural rainfall). Clay soil can benefit from mounding.