Neolloydia gielsdorfeana (Werderm.) F.M.Knuth

Mostly solitary with 4-9 spines per areole. Flowers cream with faint midstripes.

NE Mexico (SW Tamaulipas)

 

Neolloydia laui (Glass & R.A. Foster) E.F. Anders. from E Mexico (San Luis Potosi) differs most clearly in having reddish filaments.

Source: Thompson, A, ; Forbes, S.; Spencer, R. (1997). Cactaceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 2. Flowering plants. Dicotyledons. Part 1. The identification of garden and cultivated plants. University of New South Wales Press.