The type species that defines Rebutia is R. minuscula, a short-spined, red-flowered plant. This was the very first cactus I bought, at a fête, when I was in primary school, and it impressed me so much it started me off on the hobby.
My species for plant of the month, Rebutia marsoneri, is quite similar in appearance to R. minuscula, the most noticeable differences being its yellow flowers, and slightly stronger spines. Most specimens of R. marsoneri have lemon to egg-yolk shades of yellow flowers, as seen for example, in the plant of R. marsoneri v. vatteri below.
However, my plant of the month is an especially nice form of R. marsoneri, with pastel yellow flowers, a shade not to be seen in any other Rebutia. I grew this plant from seed with field number WR818, a Walter Rausch collection. Not all plants with this field number have this striking coloration, but my plant is not unique – others can be seen in an Internet search.
Unfortunatly, there is a lot of confusion in Rebutianames. As most species typically have red flowers, many growers have jumped to the conclusion that any yellowed-flowered Rebutia must be a form of R. marsoneri. However, flower colour is not a consistent indicator of species in Rebutia. So, ‘Rebutia marsoneri v. brevispina’ is probably a yellow flowered form of R. krainziana, while ‘Rebutia marsoneri v. siperdaiana’ appears to be a yellow flowered form of R. senilis. Both are shown below, for comparison.
Two things attracted me to my first Rebutia – and indeed, still do. First, they are easy to grow. Rebutias are equally adaptable to a sunny windowsill or the greenhouse. They have tolerated pretty much every compost I have experimented with over the years. They like generous watering in summer, and will withstand 5°C, and probably less, in winter; although they come from slightly warmer habitats than Aylosteras.
Second, they flower freely from a very young age, two or three years old. They are also easy to grow from seed, growing quickly. Indeed, they are usually self-fertile (unlike Aylosteras), and I quite often find self-sown seedlings in my pots of Rebutia when repotting; in most cases, they are identical to the parent plant.
All in all, Rebutias are great plants for beginners, yet still merit a large section of my greenhouse after all these years.
Ralph Martin
No part of this article or the accompanying pictures may be reproduced without permission. Copyright BCSS & the Author 2018
