I grow Wilcoxia (Echinocereus) poselgeri collected in S. TX. It needs big pots for such a thin cactus because of the tuberous roots. Enormous purple flowers, sometimes five at a time on the top of a stem smaller than your little finger. It is sensitive to sucking insects so I always use a systemic insecticide. Sometimes individual plants die in winter for no apparent reason so it is good to keep propagating it from cuttings. Others have reported this problem too. I suspect that older plants may fill their pots with the tuberous roots and suffocate. One day I'll get around to posting photos on the Wiki. monica