Name and historical fossulatus
Plants of the World Online includes Thelocactus fossulatus, Echinocactus fossulatus and Thelocactus lloydii in T. hexaedrophorus. In 2022, Sandoval-Ortega and colleagues designated an illustration published by Pfeiffer and Otto in 1843 as the neotype of Echinocactus fossulatus. The neotype establishes the reference for the former name and supports its use in synonymy. [2-WWW] [Sandoval-Ortega et al. 2022, POWO; p. 48, 50–51]
Habit, flower and fruit
The description in the 2022 paper covers spherical, flattened or short-cylindrical stems, up to 20 cm in diameter and 8 cm tall, glaucous green to grey-green. Tubercles are rounded or conical and may join into spiral ribs. Young areoles are woolly, with a short groove. Central spines are usually absent, and there are 4–8 radial spines. [Sandoval-Ortega et al. 2022, p. 48]
Flowers have a white or pink perianth. In the description, they reach 80–100 mm in diameter and 40–60 mm long. Fruits are small, spherical to cylindrical, with scale-like coverings and retained perianth remnants. Black seeds measure 1.5–1.7 mm long. These are ranges from the species description presented in this paper. [Sandoval-Ortega et al. 2022, p. 48–49]
Site in Aguascalientes
In August 2021, about 15 plants were found in the municipality of Tepezalá, close to the Zacatecas border. The site lay near Mesillas, on a northern slope at 2085 m, in dry small-leaved scrub. Specimen M.H. Sandoval-Ortega 1069 was deposited in the HUAA herbarium. It documents the first published record of the species and genus for Aguascalientes. [Sandoval-Ortega et al. 2022, p. 47, 49–50]
Climatic profile in the nine-species model
In Mosco's analysis, the species model was based on 195 records. Isothermality had a permutation importance of 66%, and precipitation in the wettest quarter 17%. Niche breadth was 0.099. Modelling preceded publication of the Aguascalientes site and describes the climatic and field dataset used at that time. Isothermality is the ratio of mean daily temperature range to annual range, multiplied by 100. [Mosco 2019, p. 3–6, tabele 1–2]
Related articles
Materials from the author's archive
The species also appears in Konrad Szychowski's private material archive. [Kaktologia 2009b, file p. 16] [Neciu b.d., file p. 1]
Synonyms and names in the literature
Echinocactus drageanus · Echinocactus droegeanus · Echinocactus fossulatus · Echinocactus fossulatus var. quadrispinus · Echinocactus hexaedrophorus · Echinocactus hexaedrophorus f. fossulatus · Echinocactus hexaedrophorus f. labouretianus · Echinocactus hexaedrophorus f. major · Echinocactus hexaedrophorus var. decipiens · Echinocactus hexaedrophorus var. droegeanus · Echinocactus hexaedrophorus var. fossulatus · Echinocactus hexaedrophorus var. labouretianus · Echinocactus hexaedrophorus var. major · Echinocactus hexaedrophorus var. subcostatus · Echinocactus insculptus · Echinofossulocactus hexaedrophorus · Thelocactus fossulatus · Thelocactus hexaedrophorus subsp. francii · Thelocactus hexaedrophorus subsp. jarmilae · Thelocactus hexaedrophorus subsp. kvetae · Thelocactus hexaedrophorus subsp. lloydii · Thelocactus hexaedrophorus var. decipiens · Thelocactus hexaedrophorus var. fossulatus · Thelocactus hexaedrophorus var. labouretianus · Thelocactus hexaedrophorus var. lloydii · Thelocactus hexaedrophorus var. major · Thelocactus lloydii [2-WWW]