Stem and flower structure
The solitary stem has distinct ribs divided into small angular swellings. Round areoles bear white felt, and the needle-like spines are whitish or brown. In the original description, their arrangement includes paired radial spines and a single downward-pointing spine. Rausch also allowed for the presence of one central spine. [Grätz 2009]
The inner tepals are yellow, spatulate and finely toothed, with orange coloration near the margins. The outer tepals are brownish pink. The floral tube and tissue surrounding the ovary are light green, with brown scales and pale grey wool. The ripening globose fruit retains its scales and pale hairs. This character combination links material to the protologue after a change in generic placement. [Grätz 2009]
Sierra Famatina and field observations
The type came from Carrizal in the Sierra Famatina at 1760 m. Rausch collected it in 1990 under the number WR 817b. Graham Charles later described plants from the same mountain range seen during a December 2000 visit. They occupied steep valley slopes where rocks or shrub roots locally stabilized loose substrate. Charles drew attention to the bluish stems and dark-haired buds visible in the field. [Grätz 2009] [Charles 2012]
Plants Charles raised from collected seeds produced flowers ranging from yellow to orange. His account documents variation in material of known origin and successful propagation from seed. He regarded its geographical separation and resemblance to Acanthocalycium thionanthum as grounds for discussing subspecies rank. In the POWO treatment followed here, the plant retains species rank. [Charles 2012] [2-WWW]
Spelling on the label
POWO records the combination Acanthocalycium keuhhasii published in 2024. The original name Lobivia kuehhasii has a different letter order and commemorates Franz Kühhas. The database links both spellings to one species. Retaining the field number with material carrying the older name helps relate its provenance to Rausch’s description and subsequent observations. [2-WWW] [Grätz 2009]
Related articles
Synonyms and names in the literature
Lobivia kuehhasii [2-WWW]