|Photo © Mark Faint|
Body light bluish-grey-green, ca. 2 cm high, to 2.7 cm Ø, with conical tapering root; Ribs divided into low rounded tubercles, but not fully, separated only by a sinuate line, resembling Lophophora williamsii; Spines only 1, (rarely with a small spine, which soon falls off), to 12 mm long, yellowish-horn coloured, dense and slightly intertwining, without a lengthways groove, Flowers ca. 1 cm long, 1.5 cm Ø; Outer perianth segments greenish, with white edge and brownish middle, pointed, smooth; Inner perianth segments narrow lanceolate, ca. 3 mm broad, pointed and with fine tips, this occasionally missing or the outer perianth segments tip split, otherwise smooth edged, matt, white, occasionally with very light and delicate pink mid-stripe, underside occasionally somewhat dark and occasionally tinted light brownish; Filaments and style pink; stamens deep golden yellow; Stigma lobes 6, pink with delicate darker centre line, underside with darker furrow; Fruit unknown; Seeds 0.75 mm long, slightly glossy, Testa completely covered with low tubercles.
Locality: south of Matehuala, San Luis Potosi, México.
Backeberg's original description is invalid because the type locality was not given and according to the ICBN this is required. The name was later validated by Lechner and Jantschgi in Turbi-Now Issue 4, 1998.
For a long time it was thought that this taxa was a synonym of T. schmiedickeanus ssp. klinkerianus fa. schwarzii, even though they look completely different and come from quite distant localities. The easiest ways to distinguish between them are schwarzii has a pale green epidermis, angled tubercles and white stigma, whereas polaskii has a brownish epidermis, flat, rounded tubercles (it looks like the plant has been inflated with a bicycle pump !) and pink stigma.
Turbinicarpus macrochele ssp. macrochele var. polaskii is part of the macrochele aggregate of taxa, together with the following: