Living Rocks of Mexico
Ariocarpus Cultivars: An Overview of Cristates, Hybrids, Monstrose Forms and Other Oddities
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This article is reproduced form The Cactus and Succulent Journal (U.S.), Vol. 71 (1999). No .4, p191-200 with the  kind permission of the Editor and Miles Anderson.



P 0 Box 6, Cortaro, AZ 85652 (All photos by the author)

In understanding the relative lack of Ariocarpus cultivars in cultivation, one needs only to compare Ariocarpus with the genus Astrophytum. Both genera are small but have interesting variations within the species and both are extremely popular. Not only do they appeal to the general public, they often take up sizeable percentages of space in the greenhouses of hardened collectors. Few other genera elicit the focused devotion of Astrophytum and Ariocarpus, yet while many interesting cultivars of Astrophytum exist, only a few of Ariocarpus can he found. The reason is threefold: numbers of seedlings grown, speed of growth and difficulty of culture. Let's take Ariocarpus scaphirostris versus Astrophytum myriostigma, for example. Most cultivars arise from seedlings and occur sparingly in even the best circumstances. Astrophytum myriostigma seed is sown by the tens of thousands annually just in the USA, and these seedlings can grow to flowering size in 2-3 years without the aid of grafting, so interesting traits can easily be magnified and selected. Seed sown of Ariocarpus scaphirostris, on the other hand, number in the tens or hundreds, and only with the aid of grafting can these plants he flowered in less than 5-8 years. Additionally, most Ariocarpus species are rot-prone, thriving only when provided with high light and heat.

Another factor that oddly enough has kept Ariocarpus from being grown in quantities commercially was the availability of collected specimens. When CITES was written in 1974, several species (A. agavoides, A. scaphirostris, A. trigonus) were placed in Appendix I (most-protected status). The remainder of the genus could be collected and exported legally until June of 1992, when they were also given Appendix I status. Until that time, truckloads of collected Ariocarpus plants flowed from Mexico to the Orient, Europe and the USA, and there was little pressure to grow plants from seed when large, old and incredibly inexpensive specimens were commonly available. The astronomical prices now being paid for cristate and even normal specimens of Ariocarpus are simply a matter of supply and demand: a growing number of collectors are vying for an ever-shrinking pool of old collected plants.

Cristate Ariocarpus

Essentially all cristate Ariocarpus plants in cultivation are mature, field-collected plants Some have been in cultivation for decades and many are easily 50-75 years old. Although any Ariocarpus species has the potential of becoming cristate, only a few species are seen in cultivation. Not surprisingly, crests of the rarer species (A. agavoides, A. bravoanus ssp. bravoanus, A. bravoanus ssp. hintonii and A. scaphirostris) seem to he without representation in cultivation. A. fissuratus and its forms, despite their great numbers in the wild, are essentially without cristate representatives in cultivation (Fig 1). Somewhat akin to stories of alligators in the sewers are the tales collectors tell of someone who once had a cristate A. fissuratus or the legendary A. trigonus crest. Cristate forms of A. kotschoubeyanus and its varieties (Fig 2) can be seen occasionally but are far from common. Cristate varieties of Ariocarpus retusus (Fig 3) are certainly the most commonly seen of the genus and often grow quite large in comparison to a normal plant.

Cristates have unfortunately withstood attempts at mass propagation. While cutting a large crest into several sections and rooting them might be a viable option, it is too slow to be of use commercially, and even the most avid would-he propagator can be loath to mutilate a healthy old Ariocarpus cristate. Grafting, then, is probably the best hope for propagating these cristates. Unfortunately, vigorous stocks can force crested scions to revert to a row of normal heads. So as yet, no cristate Ariocarpus has been propagated to any degree in the USA.

Monstrose Ariocarpus

Although it is just a matter of time until more clones of monstrose Ariocarpus emerge in cultivation, at this time in the USA there is only one clone available Ariocarpus retusus var. furfuraceus 'Monstrose' appeared commercially during the 1980s and has been carried by a number of nurseries It has several growth forms which can simultaneously coexist on the same grafted plant (Fig. 4). Beginning as a mass of small reddish heads crowned with white wool, this dwarf plant grows into a cluster, with gray-bodied heads up to about 3" in diameter (Fig 5). From time to time odd, red, tumorous growths may emerge from the sides of grafted plants. These tumors grow rapidly and then collapse upon themselves like punctured balloons. Occasionally other mutations (and even crests) are propagated from this original clone, but they are generally short-lived as well.

While not technically monstrose forms, there are other Ariocarpus oddities as well. Extreme variations in tubercles are occasionally seen in both field-collected and seed-grown plants. Some clones of A. retusus var. furfuraceus can be grossly oversized or have an exceptionally rough surface somewhat like that of a cauliflower. There are also clones which bear tubercles with twin tips, either side by side or a larger one above a smaller one.

A number of chimeras have been formed as a result of grafting. These mixtures of tissue of the Ariocarpus scion and the stock of some other cactus species are fairly unusual, certainly unattractive, and mostly unstable. This instability keeps them from being widely available.

Variegated Ariocarpus

While variegated Ariocarpus plants do occasionally arise from batches of seedlings from pure species, they are few and very far between. Moreover they are often unremarkable, showing only slight differences in color light green with dark green, or green with gray-green. The intensity of the colors often varies with the season or the light level. Very rarely does one find a clone with strongly contrasting light and dark tissue. Unfortunately, after propagating these nicely colored variegates, the propagules often end up either completely normal or solid yellow rather than maintaining the mottled pattern of the original plant

Hybridization offers the best hope for producing variegates. As anyone who has raised hybrids of Astrophytum or Ferocactus has observed, an abnormally large number of variegates appear among the seedlings, perhaps 1 for each 100 seedlings. Ariocarpus hybrids share this tendency, and the percentage of variegates increases with each successive generation. Variegated growth can also appear spontaneously on previously normal plants. For example, a variegated offset of A. agavoides x A. kotschoubeyanus sprouted from a normal, green, grafted cluster (Fig 6).

Hybrid Ariocarpus

Hybridizing Ariocarpus is quite easy, provided the parents flower at the same time. The progeny resulting from crosses between pure species are an amalgam of the parents' features, flower color, tubercle shape and texture, areole placement, mature size and growth rate. While no Ariocarpus hybrids are particularly common, perhaps the best known is A. kotschoubeyanus x A. fissuratus var. fissuratus (Fig 7). This is probably because the parents are quite common and often flower simultaneously This hybrid combines the nicest features of both parents the tightly arranged tubercles of A. kotschoubeyanus with the rough surface of A. fissuratus. When A. kotschoubeyanus is crossed with A. agavoides (Fig 8), the offspring tend to resemble the seed parent more closely than the pollen parent, but the flower is an intermediate of both parents A. fissuratus var. lloydii x A. kotschoubeyanus (Fig 9) has a great future, featuring the blunt tubercles of its larger parent, it looks like a woolly Haworthia. 

Hybrids of A. scaphirostris, oddly enough, are more common than might be expected from this rare species. Because of its scarcity, often only one specimen in a collection is in flower; and rather than see that flower wasted, the collector simply crosses it with another species. A. scaphirostris x A. fissuratus var. fissuratus (Fig 10) gets my vote for one of the most attractive hybrids it hears a rich pink/purple flower and its rough tubercles curve upward at the tips like the prow of a boat. A. scaphirostris x A. kotschoubeyanus 'Elephantidens' (Fig 11), not surprisingly, forms a diminutive plant with the long pointed tubercles of A. scaphirostris and the wooly areoles of its other parent, The superb feature of this hybrid is its flower the rich royal purple of A. scaphirostris with the open form of A. kotschoubeyanus. When A. scaphirostris is crossed with A. retusus (Fig 12), the hybrid has the appearance and rapid growth of the larger parent hut with a rich pink flower and slightly grooved tubercles.

A. retusus x A. agavoides, of all the hybrids grown by this author, showed the most variability and surprising combinations of features. The areole placement is occasionally typical of A. agavoides, somewhat near the center of the face of the tubercle, although in certain clones it is perched on a stalk (Fig 13). Odder still, the areoles in some other clones become a groove running up the center of the tubercle, often with a few short erect spines (Fig 14). The flower color varies from light pink to dark purple (Fig. 15). Many of the plants show a degree of variegation from pinks to yellows (Fig 16, Fig 17). All this variation was found in a single batch of seed On the other hand, most hybrids of A. retusus x A. fissuratus var. fissuratus (Fig 18) will probably not win any beauty contest. Often they bear distorted gray tubercles and light pink flowers. More attractive hybrids might be derived by crossing an extremely smooth clone of A. fissuratus var. lloydii with a short, fat tubercled clone of A. retusus var. furfuraceus.

Wherever you find cacti, from small cactus displays at general plant nurseries to the great varieties of species seen at plant shows or advertised by mail-order companies, only a small number are monstrose or cristate cultivars. Of these few available, perhaps a dozen species dominate: Cereus hildemannianus 'Monstrose', Cereus tetragonus 'Monstrose', Mammillaria elongata 'Cristate', etc. This disparity is not likely to change in the future, and so general nurseries will never carry a selection of Ariocarpus oddities. However, cactus and succulent nurseries will eventually carry at least a few as has occurred with the genus Astrophytum, cultivars (mostly of Japanese origin) which were seen only in books a few years ago are now available at plant shows and via mail-order. Even though it will still he a while before a wide selection of Ariocarpus can be readily purchased, there are two things the avid collector needs to keep in mind: (a) many of the original species/varieties of Ariocarpus have only been in cultivation for a few decades, if that, and (b) mutations happen.

Miles to Go

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