Mammillaria mathildae

Name and distribution

The accepted name is Mammillaria mathildae Kraehenb. & Krainz, published in 1973. POWO retains the species separately from Mammillaria fittkaui. The name M. fittkaui subsp. mathildae and the corresponding combination in Escobariopsis are synonyms. The current database range includes Guanajuato and Querétaro. [2-WWW]

The experimental site in Cañada Juriquilla

García-Rubio and Malda-Barrera describe a population on steep slopes in Cañada Juriquilla, north of the city of Querétaro, at about 1890 m above sea level. The site contained tropical forest that sheds its leaves in the dry season. A location within a protected area, near natural plants, was selected for the reintroduction experiment. The description concerns this site at the time of the study. [García-Rubio and Malda-Barrera 2010, pp. 934–935]

The 2010 article describes the species as endemic to Querétaro. The broader Guanajuato and Querétaro range in current POWO also relies on later floristic documentation. The historical location of the studied material remains unchanged, while the modern distribution description includes an additional state. [García-Rubio and Malda-Barrera 2010, García-Rubio and Malda-Barrera, p. 934. POWO, as of 11 October 2026] [2-WWW]

Seedlings and shoot regeneration

Tissue culture was initiated from a mixture of seeds from 62 mother plants. After three months, seedlings about 15 mm long were divided into apical, lateral and basal fragments. On full-strength MS medium with 30 g/l sucrose and no added BA or IAA, lateral sections produced a mean of 4.09 ± 0.13 shoots after 60 days, apical sections 1.14 ± 0.07 and basal sections 0.59 ± 0.11. Standard errors were reported. [García-Rubio and Malda-Barrera 2010, p. 934–935, tab. 1]

Lateral and apical sections regenerated without callus, which appeared in about 41% of basal sections. Adding the tested BA and IAA regulators caused strong callus formation and generally limited shoot regeneration. Conditions included 26 ± 1°C, sixteen-hour lighting and 120–130 µmol photons/m²/s. This was the response of young tissues in a specific culture, with 11 apical/basal sections and 22 lateral sections per treatment and two repetitions. [García-Rubio and Malda-Barrera 2010, pp. 934–935]

Roots and regeneration of above-ground parts

Shoots 10–15 mm long rooted at about 97% on full-strength MS without IBA and about 63% on half-strength MS. Rooting was considered positive when a shoot produced at least three roots 15 mm long. The root system developed within seven to eight weeks. Added IBA increased callus and reduced rooting in the treatments tested. [García-Rubio and Malda-Barrera 2010, pp. 935–936, Table 2]

Spontaneous shoot emergence from roots was recorded during the experiment. The authors also show plant regeneration from a root in the field. Regenerative capacity may allow above-ground parts to recover after damage. The article did not establish hormone concentrations that might be responsible for this phenomenon. [García-Rubio and Malda-Barrera 2010, pp. 936–937, Fig. 2]

Development in culture and acclimatisation

After seven months of culture, an average of about five plants was obtained from one seed. The resulting material had a mean height of 1.79 ± 0.04 cm and width of 1.37 ± 0.02 cm, with 25.47 ± 0.82 areoles. These are characters of plants produced through the laboratory procedure rather than a diagnosis of adult individuals in nature. [García-Rubio and Malda-Barrera 2010, p. 937]

Rooted plants were acclimatised in small pots with a peat substrate and perlite. An initial cover limited drying. During eight weeks in the greenhouse, 98% of plants in this batch survived. This assessment preceded transfer to the natural habitat. [García-Rubio and Malda-Barrera 2010, p. 935]

Reintroduction and the first months of survival

In October 2007, 100 marked plants were planted in a 75 × 10 m plot in Cañada Juriquilla. The first month saw the loss of 43% of the cohort, and after five months about 52% had been lost. A marked decline followed the end of rainfall. Survival at this stage was therefore clearly lower than during earlier acclimatisation with watering provided. [García-Rubio and Malda-Barrera 2010, pp. 935–937, Fig. 3]

The authors discuss the potential importance of root symbionts as a hypothesis. The trial presented neither tested mycorrhizal addition nor measured root colonisation. The field result concerns one cohort and the first months after planting. The subsequent contribution of these plants to population reproduction was not determined in this publication. [García-Rubio and Malda-Barrera 2010, p. 937]

Related articles

Materials from the author's archive

The species also appears in Konrad Szychowski's private material archive. [Hernández Martínez and Sánchez Martínez 2002, file p. 2, 3, 4, 5, 6, 7] [Hernández-Oria et al. 2003, file p. 2, 3, 6, 7, 8, 10]