Habit and morphology in the 2012 comparison
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. [Řepka and Gebauer 2012, p. 142, tabela 3]
Flowers were characterised as pale violet to intensely purple, 25–35 mm long and 30–35 mm wide. Fruits are nearly spherical to ovoid, green, sometimes reddish, and 5–8 mm long. Seeds measure 1.0–1.5 mm. This is the publication's morphological comparison, while the anatomical study covered material originating from Marathon in Texas. [Řepka and Gebauer 2012, pp. 140, 142, tables 1 and 3]
Lignified spine fibres
The spines of the plant examined had a single-layered epidermis surrounding thick-walled fibres. The surface remained free of epidermal hairs. In cross-section, fibres were rounded and had small lumina. Mean wall thickness was 4.2 µm in the epidermis and 3.8 µm in the core fibres. The values come from hydrated preparations of cultivated material. [Řepka and Gebauer 2012, pp. 139, 141, 143–145, table 2, figs. 1E and 2E]
The authors addressed an earlier description of the spines as corky. Their sections showed a structure with thick, lignified fibre walls. The anatomical assessment thus refines the impression given by the spine's appearance. The article compared sections and cell dimensions. The relationship of this structure to hardness was an interpretation, without an experiment measuring bending force. [Řepka and Gebauer 2012, p. 144]
Synonyms and names in the literature
Coryphantha hesteri · Escobaria hesteri [2-WWW]