I have one specimen that produce the main body to around 5 cm or maybe a little more. Ive had it for 22 years so its not that it havnt grown up yet. on pictures I see plants much larger. Mine are summer growing and I have have planted spare plants out into the cold cacti greenhouse where they survive air temps to -14C and climb the Cylindropuntias each summer. Would these be the nana form? Now I have sown seeds collected in Bloemfontein. Maybe these will be larger. Martin Tversted