Pelecyphora

Broad treatment and its history

POWO accepts 21 species of Pelecyphora, with the genus as a whole ranging from southern Canada to Mexico and occurring in Cuba. In classical twentieth-century works and the 2002 micropropagation experiment, the genus comprised two Mexican species, P. aselliformis and P. strobiliformis. Its expansion in the 2022 paper by Sánchez and colleagues included species of the former Escobaria and P. macromeris (previously Coryphantha macromeris). [2-WWW] [Sánchez et al. 2022, POWO, as of 11 October 2026. Sánchez et al., pp. 124–125, 129–145] [Pérez-Molphe-Balch and Dávila-Figueroa 2002, POWO, as of 11 October 2026. Sánchez et al., pp. 124–125, 129–145]

The name Pelecyphora dates from 1843 and Escobaria from 1923. When the groups were combined, the earlier name took priority. The type species of Pelecyphora is P. aselliformis. Priority concerns the choice of name for the accepted genus boundaries. The boundaries themselves result from interpreting relationships and plant characters. [Sánchez et al. 2022, p. 124–125, 129–130]

Plastid DNA and eight characters

The 2022 analysis included five plastid DNA regions, eight morphological characters and sequence-length changes. The sample contained eight Escobaria species and both classical Pelecyphora. Together with material of P. macromeris, they formed a lineage supported in the molecular analysis by PP = 0.98. PP is the posterior probability obtained for the branch under the model and dataset used. [Sánchez et al. 2022, p. 117–119, tab. 1–2, ryc. 1]

Within this lineage, P. aselliformis and P. strobiliformis were placed in a group also containing P. chihuahuensis, P. laredoi and P. tuberculosa (under the corresponding Escobaria names in the paper). The different, highly modified tubercles of the two classical species thus occur alongside a close relationship to plants with a more typical cactus surface. [Sánchez et al. 2022, p. 119, 124, ryc. 1–2]

Tubercle, groove and seed coat

A groove associated with areole organisation runs along the dorsal surface of the tubercle in species of the former Escobaria. In the two classical Pelecyphora it is vestigial but homologous, corresponding to the same structure inherited from common ancestors. In the developmental description, the shorter groove and highly modified tubercle are parts of a single morphological system. [Sánchez et al. 2022, p. 124, ryc. 3D]

The seed coat has depressions in the cell surfaces. In the former Escobaria, it was mainly the middle part of the outer cell wall that was thin and collapsed. In classical Pelecyphora, this entire wall was thin. The authors of the 2022 paper compared these two ways of forming pitted relief, which differ in cell shape and depression diameter. In P. chihuahuensis the depressions are shallow, and P. macromeris provides another exception in seed-coat sculpture. [Sánchez et al. 2022, p. 122–124]

The outer tepals of many members have finely fringed, ciliate margins. In P. strobiliformis this margin was described as a consistent character, while in P. aselliformis it may be entire or fringed. Comparing the flower, seed coat and tubercle explains both similarities within the genus and the range of exceptions to any single character. [Sánchez et al. 2022, p. 124–125]

Different sites and growth forms

The two classical Mexican species are slow-growing, low plants. P. aselliformis is distinguished by an elongated areole with an arrangement of spines resembling the outline of a woodlouse. P. strobiliformis has triangular tubercles that give the stem a cone-like appearance. Both descriptions concern this distinctive part of the genus and help identify its two historical species. [Sajeva et al. 2012, p. 27]

The current broad circumscription also includes P. vivipara and P. missouriensis (formerly Escobaria vivipara and E. missouriensis). Their North American ranges and temperature ranges differ from the habitats of the Mexican P. aselliformis and P. strobiliformis. Cultivation requirements and cold tolerance are described for specific species and plant origins. [2-WWW] [Sánchez et al. 2022, POWO. Sánchez et al., pp. 137–145]

Micropropagation of the two classical species

In 2002, a propagation method for P. aselliformis and P. strobiliformis was developed by stimulating areole meristems. The seedling fragments used produced numerous shoots on medium containing benzyladenine. After shoot elongation, rooting and acclimatisation were carried out separately. Results were reported for specific medium variants and successive culture cycles, allowing the efficiency of individual stages to be compared. [Pérez-Molphe-Balch and Dávila-Figueroa 2002, p. 73–78]

In 2016, P. aselliformis was micrografted onto Opuntia ficus-indica. With 30 apical scions, 97% graft success was obtained, compared with 81% for 270 subapical segments. The experiment shows two ways of using seedling material. The apex more often continued growing as a single scion, while segments bearing areoles produced more new shoots. [Badalamenti et al. 2016, p. 2–4, tab. 1]

Nowsza propozycja Neobesseya

In 2026, Breslin and Majure proposed reinstating Neobesseya for some species included in broadly circumscribed Pelecyphora. This is a published classification proposal linked to newer analyses. POWO, checked on 11 October 2026, still accepts broad Pelecyphora, including P. macromeris, P. vivipara and P. missouriensis. This state of the list determines the main names in the atlas. [Breslin and Majure 2026, Breslin and Majure, section on Neobesseya. POWO, as of 11 October 2026] [2-WWW]

Spines of the former Escobaria in cross-section

In the 2012 comparison, material from four species now assigned to Pelecyphora represented five units then recognised within Escobaria. In P. abdita (the paper's E. abdita), an epidermis, a subsurface zone and two fibre zones were identified. In P. hesteri, P. minima and two historically distinguished samples of P. missouriensis, the epidermis surrounded a fibrous interior. These results concern selected cultivated material and do not describe every species in the genus. [Řepka and Gebauer 2012, p. 138, 141, 143–145]

Unicellular, unbranched hairs occurred on the spine surfaces in both P. missouriensis samples. The hairs of material from Holbrook, Arizona, were longer and often curved, while those from Electric, Montana, were shorter. The samples were identified as E. missouriensis subsp. navajoensis and subsp. missouriensis, respectively. Spine surfaces in the examined P. abdita, P. hesteri and P. minima lacked these outgrowths. [Řepka and Gebauer 2012, p. 139–140, 143–145, tabela 1, ryc. 1–2]

POWO includes the former name subsp. navajoensis within P. missouriensis subsp. missouriensis. The subspecies name is shared, while the results of the two samples retain their own origins and measured values. This approach allows older literature to be read without assigning one character to the entire taxon as currently circumscribed. [2-WWW]

Related articles