Name and identification
The accepted name is Ariocarpus agavioides (Castañeda) E.F.Anderson. Combination authorship follows IPNI, differing from the E.S.Anderson entry in POWO. Scientific and collectors' literature often uses the older spelling agavoides, and the former genus name is Neogomesia. [3-WWW] [2-WWW]
Narrow, relatively smooth tubercles and a woolly areole on their upper surface distinguish this plant from the strongly wrinkled A. fissuratus. Young A. bravoanus can show similar tubercle elongation. Several features and the plant's developmental stage therefore matter in identification. [Hernández and Anderson 1992] [Romulski 2006b]
Distribution and substrate
POWO gives a range from Tamaulipas to San Luis Potosí. Regional Tamaulipas studies described sites near Tula at elevations of 900–1200 m above sea level. They had limestone substrates prone to erosion, with little organic matter. This elevation range refers to the region described. [2-WWW] [Martínez-Avalos and Suzán-Azpiri 2000]
Associations with nurse plants and few seedlings were observed at the sites. A nurse plant can alter sunlight and conditions near the soil surface. Co-occurrence itself must nevertheless be distinguished from an experiment directly measuring the effect of shelter on survival. [Martínez-Avalos and Suzán-Azpiri 2000]
Flowers and reproduction
In the seven-species comparison, mean flower width in A. agavioides was 26.53 ± 1.24 mm for a sample of 35 flowers. Variation is the standard error of the mean. This measurement comes from one selected population and is not a limiting flower size for the entire species. [Martínez-Peralta et al. 2014a]
Pollination with other individuals' pollen favoured fruit formation. Manual self-pollination gave much poorer results, although it was not entirely ineffective. Pollen tube observations indicated partial rejection of self-pollen. A pollen tube is the structure through which sperm cells reach the ovule. [Martínez-Peralta et al. 2014b]
Growth rate and first flowering
Cristian Neciu described the first flowering of seed-grown plants at three years old. This was a result from his collection and method, which included prolonged protection of young seedlings from drying. The age in the account is not a deadline every plant should meet regardless of conditions. [Neciu 2006]
Experience from a Polish collection
Jerzy Kłosiński described plants in their teens growing on their own roots in a mineral substrate of stones, gravel and clay. They spent summer outdoors, with the option of protection from cold, prolonged rainfall. At the end of September, he moved them to a south-facing windowsill, where they completed bud development and flowered. [Kłosiński 2005]
Under his conditions, fruits ripened in winter and early spring, and plants remained on the windowsill. He separately recorded grafted seedlings flowering in their second year. This experience concerned A. agavioides and a particular collection. It demonstrates successful cultivation without a large greenhouse, without assigning the same tolerance to all ariocarpus plants. [Kłosiński 2005]
Cultivation and repotting
The starting point for adult plants is a permeable substrate and watering under conditions that allow it to dry. The Polish cultivation account recommended mineral components with stable structure, careful handling of thick roots and a dry, cool rest. Watering frequency was linked to weather and drying of the pot. [Anonim 2006]
On a sunny windowsill or in a greenhouse, gradual increases in sunlight after a period of weaker light are important. Young plants from enclosed sowing conditions move gradually to drier air and stronger light. This environmental transition is described in the account of cultivating the genus. [Neciu 2006] [1-WWW]
Sowing and pollination in a collection
In Neciu's account, seedlings remained in sealed bags for 12–18 months. Success depended on cleanliness, temperature and protection from excessive light. This extended period is part of a particular practice requiring monitoring of seedling condition. [Neciu 2006]
When obtaining seeds, keep records of both parent plants. Controlled pollination results indicate the advantage of crossing different individuals. Pollen from a second offset of the same plant may not provide the genetic difference needed to overcome incompatibility. [Martínez-Peralta et al. 2014b] [Clark et al. 2018]
Organ separation and behaviour of self-pollen
In measurements of the Tula population, Ariocarpus agavioides (A. agavoides in the publication) had the largest mean height difference between pistil and stamens among seven species, 5.02 ± 0.25 mm, for 35 flowers. Variation is the standard error of the mean. The distance describes spatial separation of the organs. Self-pollen compatibility was tested in a separate experiment. [Martínez-Peralta et al. 2014a, pp. 665–670, Table 1]
After manual self-pollination, pollen tubes were found in the ovary of 25% of 28 pistils examined, while fruit set was 6.9% in a separate sample of 29 flowers. Self-pollen often germinated on the stigma before its growth was inhibited in the style. Arrest of the tube after germination begins explains why visible pollen on the stigma can coexist with poor fruit set. [Martínez-Peralta et al. 2014b, p. 532–536, ryc. 3–4, tabela 1]