As with many South American cacti genera, there is much discussion and dispute about the makeup of the genus Rebutia. It really depends on your position as either a splitter or a lumper. Merv Whitehouse summed up the situation very well in his presentation on Parodia — you will tend towards either the ‘Old Testament’ or the ‘New’ (see Merv’s article in Dinteranthus 13[8]).

The CITES Checklist recognises 29 accepted species and 9 provisional ones (it appears that there might be a couple more which were left out by mistake). In reaching these figures, five previously recognised genera—Aylostera, Digitorebutia (sometimes called Mediolobivia), Rebutia, Sulcorebutia, and Weingartia have been merged to form the presently recognised genus of Rebutia. I am sure that the battle of names will continue but as a Society we have accepted the CITES classifications so for our purposes, all of the aforementioned genera will be regarded as Rebutia. From a collector’s point of view, they are all very similar and originate from the same general geographic area and have similar cultivation requirements.

[Top of Page]

Rebutia haagei v crassa
[Photo by John Ellis, BCSS - Teesside Branch, UK]

The plants come from Bolivia and Northern Argentina, growing in mountainous country on the eastern side of the Andes Mountains at altitudes of between 1500-4000m AMSL, a situation which subjects plants to a wide diurnal temperature range and fierce sunlight high in ultra-violet rays.

Plants are described as small globular cacti, many of which form large clusters. It would appear that in cultivation they grow larger and cluster more vigorously than in habitat. There is a variety of body forms and spination. Plant body characteristics can be from densely spined to the less densely spined and warty tubercled. The crowns tend to be devoid of spines and wool. The spines are usually soft to the touch—not your classical vicious cactus. The sap is never milky. Most of my Rebutias show a tendency towards being short columnar plants. This may be due to a reduction in light intensity with the aging of my plant roof material.

Rebutia heliosa (grafted) - Photo by Paul Kaluschke

As with many other genera, subdivisions have been established within the main classification but even here there are disagreements between various authors. Those who are interested in this aspect should refer to the appropriate texts.

Rebutias across the board have flowers which are relatively large in relation to their bodies. Flowers are borne low down on the body and are in the brilliant red, orange, or yellow range. However, there are some which are white or near-white (R.leucahtema and R.heloisa var narvaecensis [syn espinosae]). Flower width is in the 1.5-4cm range.

According to most writers, cultivation is easy and the genus is recommended for beginners. This has not been my experience and I have found them difficult to keep going. This does not surprise me all that much though, when we consider their habitat conditions compared with those we have here in Brisbane. It would be interesting to hear from other members about how their Rebutias have fared in their particular conditions. A short article or perhaps a letter to the editor of Dinteranthus would be valuable.

Recommended growing conditions call for a gritty, porous mix with a pH slightly on the acidic side. Strong light is essential. Plants will accept heavy watering during warm weather but do allow the pot to dry out between waterings. Remember that the most common cause of trouble with growing Rebutia is overwatering. In habitat they grow on steeply sloping ground where water rarely stands for any length of time. Rebutia will take low temperatures when dry and do require a winter rest period.

[Top of Page]

Although Rebutia will survive infrequent repotting, it is better that they are repotted regularly (particularly when the plants are young). Repotting will increase the number and size of stems and will increase the number of flowers produced. Half pots (where the width is greater than the depth) are recommended, even for the thick-rooted species which rarely push their roots down more than 100mm or so. Repot yearly until reaching about 100mm in size, then every two or three years will suffice. Be guided by the size of the plant in relation to the pot. Repotting is best done at the end of winter but can be done at other times. Do not water for a couple of weeks after repotting to reduce risk of root rot via broken roots.

Propagation is by seed or vegetative methods. Seeds germinate readily but be aware that viability drops rapidly when the seeds are more than 12 months old. Rebutias hybridise readily so it is possible that your treasured plant may not be true to the name on the label. This has been noted in wild populations and has given rise to a great many names for plants which are essentially the same species.

Rebutias are subject to the same range of pests and diseases as other cacti; mealy-bug in particular and fungus and rot problems brought about by overwatering and high humidity. On this last point, I think we need to be particularly careful about watering during the period of high humidity which we experience here during mid-summer.

[Top of Page]

The Cactus File Handbook 2: Rebutia by John Pilbeam confines itself to the pre-CITES Checklist. The book is recommended as a first class reference for that group of plants which made up the old genera. Unfortunately, the book is expensive in Australia, being about $110  (softbound) and $130 (hardcover) after postage and packaging.

["Since this article was written, the hardbound version of the book has gone out of print and the softbound version has been reduced in price. Based on February 2003 conversion rates, it should be possible for people in Australia to buy the book from us using their credit card for around $70-75, including postage and packaging." - ROGER LABBETT, publisher]

The illustrations are very good and Pilbeam brings together the many new plants found over the past thirty odd years. There is a good reconciliation of collector’s field numbers with other named species. There is a mention of R.haagii and its varieties, its relationship with R.pygmaea (R.haagii is one of those omitted from CITES). This species also receives much attention from the Preston-Mafhams in their book, Cacti—The Illustrated Dictionary (see p.198).

To me, all Rebutias are attractive plants, especially when in full flower. I feel it would be hard to single out recommended species but there is one which, judging from the photographs, would be nice to have. This is R.spegazziniana with its dark, blood-red flowers and white stigma which bend over and lay along the petals.

Rebutia sp. - Photo by Paul Kaluschke