Range and habitat of the populations studied
POWO accepts Turbinicarpus lophophoroides as a species of northeastern Mexico, with a range reaching Jalisco. Its basionym is Thelocactus lophophoroides. [2-WWW]
Flores and colleagues describe populations on low-lying plains of San Luis Potosí, covered with grasses, periodically flooded and associated with saline ground. [Flores et al. 2008, opis siedliska]
The systematic publication places T. lophophoroides in present-day Turbinicarpus. In the 2019 analysis, it also appears in a reconstruction of lineage dispersal from the Altiplanense province. The model result presents a hypothetical range history within the inferred phylogenetic tree. [Vázquez-Sánchez et al. 2019, p. 409–411]
Spines and stem surface
In Mosco's study, radial spines had a woody texture and smooth surfaces on individual epidermal cells, while the epidermal layer was divided into separate elements. Fibres inside varied in wall thickness. The material came from seeds BZ 25, with Las Tablas in San Luis Potosí as the locality, and was grown in the author's collection. [Mosco 2009, p. 121–123, tab. 1–2]
Stem epidermal cells viewed from above had a polygonal outline of similar dimensions in both directions, with wavy side walls. Prismatic crystals occurred beneath the epidermis. These features belong to stem micromorphology and can be compared with other species using preparations and electron microscopy. [De la Rosa-Tilapa et al. 2019, wersja online, p. 2–3, ryc. 1D]
Vascular bundles in the cortex
Small cortical bundles were amphicribral. A phloem layer surrounded their xylem. This arrangement was also found in T. alonsoi and Rapicactus subterraneus (called Turbinicarpus subterraneus in the study). The bundles lie in parenchymatous tissues with photosynthetic and storage functions. Conduction in this region forms part of the spatial organisation of a succulent stem. [De la Rosa-Tilapa et al. 2019, online version, pp. 2–4]
The main stem xylem was fibre-free. Vessels were accompanied by wide-band tracheids and non-lignified rays. These observations show the tissue arrangement in the specimens studied. Responses to periodic flooding or salinity require physiological experiments separate from the anatomical description. [De la Rosa-Tilapa et al. 2019, wersja online, p. 3–4]
Germination and seed batches
Stored batches of T. lophophoroides from different years differed in germination. The oldest control batch gave the best result. Collection year links storage duration to initial seed quality. The hypothesis of a persistent seed bank requires separate testing in soil. [Flores et al. 2008, full text, methods and discussion]
Korzenie jako model badawczy
Adventitious and transformed roots were studied for the expansin genes EXPA7 and EXPA18 and the extensin gene EXT10, associated with the cell wall. The abstract of the 2021 study describes increased EXPA18 expression under osmotic, heat and cold stress, decreased EXPA7 expression in transformed roots and undetected EXT10 expression. These are gene-activity data from root cultures. Their causal role in whole-plant resistance remains a subject for further study. [Martínez-Vázquez et al. 2021, abstract]
Related articles
Synonyms and names in the literature
Thelocactus lophophoroides · Strombocactus lophophoroides · Neolloydia lophophoroides · Pediocactus lophophoroides · Toumeya lophophoroides [2-WWW]