Pelecyphora

In Řepka and Gebauer's comparison, Pelecyphora abdita (Escobaria abdita in the account) has a small above-ground part, about 25 mm tall and 20 mm wide. Tubercles measure 10–14 mm. The authors describe a spherical to turnip-shaped, slightly branched storage root reaching up to 10 cm long. Much of the plant remains below ground for most of the year. Offset production was associated primarily with damage to the apex.

(J.M.Coult.) D.Aquino & Dan.Sánchez

A low Mexican cactus with elongated areoles and a spine arrangement resembling tiny woodlice. It is the type species of Pelecyphora. Its slow growth prompted researchers to develop propagation from areoles and micrografting of small seedling fragments.

A small, densely spined cactus of northern Mexico, called Escobaria chihuahuensis and Coryphantha chihuahuensis in earlier accounts. A DNA study placed it close to the two classical Pelecyphora, while an ecological model indicated potential habitats in Chihuahua.

(Engelm.) Stock

(Britton & Rose) D.Aquino & Dan.Sánchez

A species whose seeds contain unusual lignin dominated by 5-hydroxyguaiacyl units. The chemical publication describes it under the former name Escobaria dasyacantha.

(Hester) D.Aquino & Dan.Sánchez

(Quehl) D.Aquino & Dan.Sánchez

Pelecyphora hesteri (Escobaria hesteri in the paper) was described as an offsetting plant, with an adult stem about 70 mm tall and wide. In the comparison, tubercles reach 12–25 mm. Each areole bears 14–20 spines 5–15 mm long. The whitish, initially translucent spines become grey over time, and their tips may be purple.

(Glass & R.A.Foster) D.Aquino & Dan.Sánchez

A Mexican species whose seeds examined contained unusual 5H lignin units. It appears as Escobaria lloydii in the 2013 paper.

A species from the southern United States and northeastern Mexico, formerly included in Coryphantha. Plants maintained in culture and acclimatised in a greenhouse were used to compare compound profiles in roots and above-ground parts by chromatography coupled with mass spectrometry.

Pelecyphora minima (Escobaria minima in the account) was described in the 2012 comparison with a stem about 25 mm tall and 6–17 mm wide. Tubercles were 5–6 mm long. Each areole bore 14–27 short, strong, white spines, usually 3.5–6 mm long. Flowers were reported as deep pink to purplish pink, and seeds were 0.8–1.0 mm long.

Řepka and Gebauer's study included two samples of Pelecyphora missouriensis. The plant from Electric in Park County, Montana, was identified as Escobaria missouriensis subsp. missouriensis, and the plant from Holbrook in Navajo County, Arizona, as subsp. navajoensis. The material was kept in cultivation, and its provenance was given in table 1. All anatomical observations concern these two samples.

(W.H.Earle) D.Aquino & Dan.Sánchez

A species from the southwestern United States and northeastern Mexico. The former Escobaria albicolumnaria, examined for seed lignin, is now a synonym of its nominate subspecies.

A low cactus whose triangular tubercles form a cone-like body. In older literature it bears the name Encephalocarpus strobiliformis. It is one of the two classical Mexican Pelecyphora for which efficient propagation from areoles was developed.

(Engelm.) D.Aquino & Dan.Sánchez

A species with a broad range from southern Canada to northern Mexico. In the chemical comparison of seeds, material formerly distinguished as Escobaria vivipara arizonica and neomexicana contained typical G/S lignin.

A species from northeastern Mexico. Its seeds examined combined 5H lignin units with syringyl units, distinguishing them in the chemical comparison of Cactaceae.