Ariocarpus – Collectors’ choice slow growing Mexican rarities “Living Rocks”
Ariocarpus Scheidweiler (1838)
Ariocarpus is a small genus of unique plants whose morphology resembles the rocks and terrain of their natural habitat, hence their common name “Living Rocks of Mexico”. In addition to their rock-like appearance, their structure incorporates outstanding geometric forms and displays a high degree of symmetry, resulting in the astonishing morphology and beauty of this genus.
Natural Taxa and Variants
Ariocarpus grow primarilly in northern Mexico, with the exception of A. fissuratus which spreads across the Rio Grande into southern Texas.
The genus contains at least nine distinct species (only seven officially recognized) and a plethora of subspecific taxa, subspecies, varieties and forms. If we also consider the innumerable distinct geographic variants and ecotypes, the collector has a vast menagerie of beautiful living rocks to grow.
Authenticity, purity and diversity of available Ariocarpus seed is the major obstacle that the collector faces in assembling a diverse and genuine collection, representative of the breathtaking genetic and phenotypic wealth found in nature.
Seed Production
Production of high purity seed is a painstaking process, requiring precautions such as exclusion of insect pollinators or accidental pollen transfer and careful hand pollination, documentation, harvesting and processing. Maintaining the purity of geographic variants in captivity is very difficult since contamination with pollen from the same species is often undetectable, the risk increases in every subsequent generation bred in captivity.
Our Ariocarpus seed is, in many cases, produced on a small number of parent (P) plants grown from a very limited amount (usually a dozen or two) of habitat collected seed. This seed we offer is of the highest possible purity and is designated as F1 (first filial generation) in the description.
In some cases, for example endangered species and small populations, the quantity of habitat seed collected is intentionally limited to less than 10 seeds and thus, as little as two P plants may be raised in captivity. In this case, seed production involves both parent plants and highest purity F1 plants, this seed is described as F1+BC (F1 + backcross) and it is practically of equal purity as F1 seed. The same descriptions apply to plants raised from such seed produced in cultivation, when available.
All material, seed and plants, is artificially propagated in Greece (CITES licensed). We do not offer habitat seed or plants. Plant poaching is a criminal activity that has led to the demise of many wild Ariocarpus populations and brought two species to the brink of extinction. Not to mention the recent onslaught on South African succulents. Collectors should condemn and discourage this practice: never buy poached plants and harass the illicit sellers for doing so.
Cultivars
The wealth of natural taxa and forms has been augmented in recent years by human intervention by the creation of cultivars by selective breeding, a process that in ariocarpus may take a lifetime.
Obtaining original uncontaminated cultivar material is problematic, since much of the available horticultural material is contaminated, either by intention or bad practice, by pollination with foreign or inferior quality pollen. For authentic cultivar stock one must resort to the original sources in Japan or Thailand. We offer a limited amount of seed from authentic imported parent plants and this seed is designated as F1 (first filial) in the description.
A number of novel attractive Ariocarpus cultivars is being actively created here in Greece and seed supply is currently very limited, however, occasionally we will be able to offer seed from these new gems. For these cultivars, the customary designation F2, F3, etc is used indicating the number of selective crosses that was needed to achieve the desired phenotype. The higher the F number, the more intense the selected traits that characterize the cultivar. Some cultivars can be stabilized very quickly, while others may require several generations of selective breeding.
Ariocarpus germination
Growing Ariocarpus from seed is not as challenging or problematic as it is often said. In general terms the germination methods used for the so called “difficult” Mexican cacti are suitable for Ariocarpus as well. There are three points that require our attention:
- For best germination, Ariocarpus require a significant fluctuation between daytime warm (not hot) and night cool temperatures. Depending on your particular setting, temps should range from 26-29oC in the day and below 18oC at night.
- Ariocarpus seedlings spend the first 2 years of their lives mainly building their underground tuberous root to ensure water supply during dry spells. Until this is achieved, the seedlings benefit from a humid closed environment that provides constant humidity, at least during their first year of their lives. Thus the “baggie” method, along with sterile techniques including surface sterilization of the seeds, is highly recommended.
- Ariocarpus, are programmed not to germinate altogether in the same year. So, plan to leave them undisturbed in the same pot for 2-3 years post-germination (if the “baggie” method is used, after opening add a thin layer of fine gravel and leave undisturbed, exposed to seasonal fluctuations, with normal watering). An ideal germination rate could be 40%-20%-10% or 30%-20%-20% for the first three years, but germination could go on for longer. This is especially important since much of the seed we offer is only one generation “away” from habitat (F1) and therefore, there has been no cultural selection for rapidly germinating genotypes (long cultivated material may sow higher rates of immediate germination). As sown in the photo, field seed still germinates equally well, if not better, after four years of sowing. They follow their ancestral instructions for habitat survival, that is “don’t play all your cards at once”.
Having said this, if you do not have much experience in sowing you can start by having a look at these two articles, Laras, A. 1999. Growing Ariocarpus From Seed. Cact. Succ. J. (U S )Vol. 71 No .4, p210-215 and Quail, D. 2002 Slow Growing Cacti From Seed, Some Further Observations. B.C.S.S. Journal Vol 20 (2) 69-75 and many more available in the literature. If you have a tried and tested method, stick with it, keeping the above three points in mind, there is always room for improvement via experimentation. We will be happy to have your feedback and answer your questions.
