Notes on Monolluma hexagona

It has been flowering since the past weeks and today, I am finally able to create a post for it- when it's already down to its last head of flowers. Monolluma hexagona hails from Saudi Arabia, Oman, and Yemen and is said to grow on shallow soils in between stone outcrops. It was originally described as Caralluma hexagona by John Jacob Lavranos in 1963 but moved to Monolluma in 2002 by Ulrich Meve and Sigrid Liede. In 1995 it was placed in the genus Sulcolluma by Darrell Charles Plowes and just last year Peter Vincent Bruyns transferred the taxon to Ceropegia, a move that has not met wide acceptance.

Monolluma hexagona is a much-branched succulent and grows to around 20 cm tall; old specimens are matting plants with stout underground runners that give rise to more growths. You'll often see references to this plant as being difficult to grow, and indeed, it appears to demand a bit more attention compared to other stapeliads. This is a plant that can withstand a lot of sun, but heavy rains can turn the plants into mush, even with a very free-draining medium. Remember those subterranean rhizomes? If it stays wet for a longer time than necessary, then expect the worst. Another stapeliad that I have with such underground storage, Orbea baldrattii, is much more resistant to moisture, even typhoon conditions. When repotting the plant, be very careful not to break any of the roots and do not water the plant afterward, not even a slight misting. Then place it where it can receive bright light but not full sun, yet. I honestly don't think air drying should be standard procedure with succulents especially stapeliads, as long as you exercise common sense. Air drying may actually be much more stressful to the plant. Think of a fish out of the water.

Cuttings are also tricky to root, and even well-callused stem pieces can quickly rot once potted. My suggestion: place those cuttings on a very dry medium and withhold watering until you can feel some resistance when you gently tug the stem/s. Only then can you start watering the cuttings, but very minimally at first.

This is a very variable species and not a few taxa have been named from several of its populations. Some have cilia at the tips of the corollas, as with Caralluma foulcheri-delboscii, or a darker base color with dark triangles at the corolla ends like in C. shadhbana and its varieties. However, there exist plants with intermediate characters and it has been reported that specimens with ciliate corollas occur together with plants that do not have such appendages. What this means is that there is a continuum of characters from even a single population that recognizing separate species or varieties is not warranted. This illustrates why studying plants in the wild is essential before describing a species as new. One cannot just describe a new taxon without having a good idea of a supposedly closely related species' range of variations.

Those flowers are small, being less than 2 cm in diameter, but because these are borne close to one another, the small individual size is somewhat negated. Strangely, the first time I had a whiff of the blooms I thought they smelled sharply sweet- until people started pointing out that it reeked with a scent of smelly feet and my nose started to reconsider. Still, there are times of the day when I do not find the odor very offensive at all, usually by mid-afternoon when the stink tapers off. However, it's a different story during the morning hours all the way till noon, when the flowers are at their most vile olfactorily. The flowers last for a little over two days. I can imagine this plant looking quite spectacular if covered with flowers, however, the heads do not all develop at once. So that is the goal for my plant, multiple heads mature enough to bloom at the same time. I'm still not sure how I can coax it to do that, but let's see.