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By William Scheick |
ot of this earth! That was my impression the first time I ever saw succulent euphorbias.
These improbably shaped plants struck me as imposters – grotesquely twisted and bizarrely deformed cactus-imitators. Many of them looked like botched attempts at mimicry, as if they were alien life forms trying to blend in and disguise whatever they actually might be.
Strange Forms
Weirdly-shaped euphorbias could easily have served as background props in 1950s science-fiction films set on other planets. Segmented E. gymnocalycioides and ribbed E. obesa bring to mind the crashed space-sphere in the film Man from Planet X (1951). It can take me a moment to re-see these succulents more familiarly as, perhaps, pincushions.
Even so, trying to normalize the appearance of euphorbias isn’t easy. There are, for example, the menacing features of E. decaryi with what appear to be silvery arms equipped with searching maroon tentacles.
Oddly out-of-place vegetable sea anemones are suggested by E. balsamifera and E. cylindrifolia. Equally fantastic in form, E. kondoi appears to be planted upside down with desiccated roots thrust ridiculously skyward.
Even the less weirdly-shaped euphorbias also give an impression of strangeness. Gnarled stem stubs define E. clivicola, whereas peculiar twists and outlandish contortions characterize E. tortilis and E. ingens ‘Monstrose.’
What force, it might be wondered, melted E. pseudocactus? Are E. antisyphilitica (candelilla) and E. platyclada terribly leaf-impaired? Both look less like plants than like bare green sticks or brown twigs bleakly stuck into dirt.
When euphorbias produce leaves, often their foliage can be so small that they are hardly noticeable. In some cases, such as E. clava, leaves emerge only at stem tips, resulting in a peculiar drooping-propeller look – as if they were flawed imitations of some real plant.
Strange Facts
It might be tempting to think that a floral group so peculiar in its forms would be relatively scarce. This is not true for euphorbias. Very much of this earth, they include more than 2,000 species spread across our planet, including Texas.
Although succulents dominate this family, they are only part of the euphorbia story. There are also shrubby (herbaceous) species called spurges.
Perhaps the best known spurge is the poinsettia (E. pulcherrima) commercially prevalent every December. A wild Texas Hill Country relative (E. cyathophora) is a small-flowered version of this seasonal bestseller.
The nine different euphorbias populating the Texas coast are hard to recognize. But farther north in our state snow-on-the-prairie (E. bicolor) and snow-on-the-mountain (E. marginata) are prominent and showy wildflowers which have also found a more "cultured" place in Mediterranean gardening.
The yellow-flowered gopher plant (E. rigida) is an increasingly popular sprawling spurge for dry gardens. Five-foot showy cultivars of a European milkweed spurge (E. characias ssp. wulfenii) have likewise found a place in water-wise Texas landscapes.
Spurges benefit from direct exposure to morning sunlight, whereas succulent euphorbias require bright, indirect light. Excellent drainage is essential for both, and their roots prefer cool niches under rocks. Besides a little water now and then, they require little else.
Euphorbia flowers tend to be exclusively male or female. They are also completely or nearly "naked" – a bare (male) stamen or a bare (female) pistil. This is believed to a developmentally primitive design for plants. Often, in fact, euphorbia flowers can be so small and drab that only a fly or a botanist would likely notice them – or care to.
Euphorbias produce a milky sap, a liquid which distinguishes them from cacti. This poisonous latex can cause skin rashes or blisters. So gloves and protective eyewear are advised when handling euphorbias, especially if any cutting is planned.
Strange Succulents
The most well-known semi-succulent euphorbia is probably crown of thorns (E. milii), a showy houseplant from Madagascar. It’s an unusual looking plant with long, slender stems protected by stout spines.
But gracing these sprawling thorny branches are red-margined green leaves which are larger than usual for most similar euphorbias. If its tiny flowers typically lack distinction, the bright pink or yellow modified leaves (bracts) produced just below each flower add a touch of exquisiteness to this popular euphorbia.
Perhaps the next most familiar succulent euphorbia is the so-called living baseball (E. obesa) from the Cape region of South Africa. It is an eight-ribbed sphere with attractive transverse red-purple bands.
E. meloformis, also from the Cape region, offers a more distinctly ribbed orb with green-white bands. Over time both of these solitary euphorbias can become more elongated in form and even produce rudimentary leaves.
The so-called pencil tree or milkbush (E. tirucalli), able to reach 5 or 6 feet high, is another familiar potted euphorbia. Its very tiny foliage appears on branch tips, then soon falls off.
There is an especially colorful variety of the pencil tree called sticks of fire. It is distinguished by thin red-gold branches. During summer this African succulent, which can be featured in planter combinations, tends toward bright yellow.
The yellow-leaf bush euphorbia (E. leucodendron) is pencil-thin, as well, but with more ornamentation. This foot-high spineless African succulent is ornamented with red stem freckles and tiny flowers at its "fingertips."
For a closer resemblance to cacti there is E. aeruginosa. This beautiful multi-branched, heavily spined succulent from South Africa reaches about a foot high and parades tiny yellow flowers on the tips of its stems.
Closer to home is the Texas native candelilla (E. antisyphilitica), another pencil-thin euphorbia. It is also known as wax plant, especially in the Big Bend region, where it has been commercially valuable in the production of a variety of goods. The waxy coating of its leafless stems prevents water evaporation.
Candelilla is not fussy if it is given excellent drainage and summer afternoon shade. In fact, this horsetail look-alike was once more prominent in the wild throughout our state, where it endures light frosts.
Some gardeners enjoy growing thick clusters of candelilla’s leafless vertical stems either in the ground or in containers. They look even better, in my opinion, mixed with compatible companions, such as sedum, sempervivum and echeveria.
In pursuit of forms even more unusual than already naturally provided by euphorbias, growers have produced many curiously shaped grafts and hybrids. Euphorbia collectors can’t get enough of them – something to keep in mind before becoming too attached to any member of this plant family. It is almost impossible to be satisfied with just one, or two, or three or – how high can you count?