Spelling and stem features
The current POWO record accepts Ariocarpus scaphirostrus Boed. Cited studies often use scaphirostris, and older material also uses scapharostrus. These spellings lead to the same atlas profile. [2-WWW] [Mandujano et al. 2007]
The plant has a small stem and elongated tubercles projecting between rock fragments. Their variable number and arrangement meant that stem diameter and tubercle number were related measures of individual size in the demographic study. Diameter alone was subsequently used to define developmental classes. [Mandujano et al. 2007]
Restricted range and rocky substrate
The species is associated with Nuevo León. The demographic paper describes a population near Rayones on substrate of disintegrating limestone fragments. Plants formed clusters, and their occurrence was limited to a particular habitat arrangement. [2-WWW] [Mandujano et al. 2007]
The size of the surveyed area and the number of plants found describe a local population. They are not a complete census of all individuals of the species. This distinction matters when comparing older and newer threat assessments. [Mandujano et al. 2007]
Flowers and cross-pollination
Flowers are magenta. In the seven-species comparison, mean flower width was 30.01 ± 0.59 mm for 27 flowers. The authors gave the mean and standard error. A relatively low ovule number distinguished the studied population from larger species of the genus. [Martínez-Peralta et al. 2014a]
In the pollen tube growth study, A. scaphirostrus showed particularly strong rejection of self-pollen. Cross-pollination results were much better. Individual measures, such as tubes reaching the ovary and fruit formation, were assessed separately. [Martínez-Peralta et al. 2014b]
Seeds and light
The experiment described in the demographic paper compared seeds on agar in light and darkness. Germination occurred in the light treatment and was not recorded in darkness. This dependence of germination on light is called positive photoblastism. [Mandujano et al. 2007]
The result supports giving seeds access to light during sowing. It does not determine one appropriate light intensity for seedlings. In his cultivation practice, Neciu sheltered young plants and increased sunlight as they developed. [Mandujano et al. 2007] [Neciu 2006]
Longevity and population conservation
The authors of the paper published in 2007 analysed 736 plants. They recorded no deaths during the short observation period, and the model indicated relative stability. Earlier information nevertheless suggested severe losses. For a long-lived plant, one observation interval gives a limited picture of risk. [Mandujano et al. 2007]
Survival of existing individuals mattered most for population persistence. In the model analysis, loss of these plants was particularly significant. Protection of adults and opportunities for new seedlings therefore concern different, complementary parts of the life cycle. [Mandujano et al. 2007]
Stem anatomy
Sections of this species showed clusters of terminal tracheids near the outer stem cortex. These are groups of conducting system cells with a structure differing from ordinary narrow bundles. Their function remains unresolved, although several interpretations have been proposed. [Mauseth 2018]
Cultivation and first flowers
The rocky habitat provides context for using a permeable substrate. Polish cultivation literature emphasised pot drying, warm conditions during watering and root protection during repotting. Loose potting substrate and a rock crevice nevertheless differ in their temperature and water balances. [Mandujano et al. 2007] [Anonim 2006]
In Neciu's collection, seed-grown plants first flowered at five years old. He kept seedlings in a sheltered sowing environment for a long time. The result refers to his material and method. The full description of seedling care appears in the account of cultivating the genus. [Neciu 2006]
A model accounting for observation length
Mandujano's team mapped 736 Ariocarpus scaphirostrus (A. scaphirostris in the publication) across 2925 m² in Rayones. A model from the short interval without recorded deaths gave λ = 1.07, an estimate close to population equilibrium. Adding assumed mortality based on other cacti reduced the estimate to λ = 0.94. Both results had broad intervals including equilibrium. The second treatment simulated the effect of mortality not observed in this series. [Mandujano et al. 2007, p. 1036–1040, tabele 1–2]
The authors compared their census with a historical estimate of about 4000 plants on two hills. During later searches, they found one large population. This change in the known resource explains their conservation concern despite high survival during the short observation period. Results concern research completed before publication in 2007. [Mandujano et al. 2007, p. 1036, 1038–1042]
Two measures of the response to self-pollination
No pollen tubes were found in the ovaries of 37 self-pollinated pistils, but one of 50 self-pollinated flowers fruited in a separate experiment. Material examined microscopically was fixed and could no longer be observed for fruit set. The comparison indicates a very strong limitation of reproduction using self-pollen in the population studied, with different sensitivities and sample sizes in the two tests. [Martínez-Peralta et al. 2014b, p. 532–536, tabela 1]