Hi I do not know Bowiea at all, except for the pictures, and specimens seen at the botanical gardens. From the distribution range one can presume that ssp. gariepensis could be much hardier and probably smaller, rainfall to the east of the distibution is summer rainfall, to the west winter (less than 150 mm per year throughout the range, probably closer to 90mm). This distribution hugs the Orange river (also called the Gariep River) so very high temperatures (in summer in the high 40 degrees C, even into the 50's), winters moderate days, nights cold, with little frost. Probably fairly high dew levels.Altitude (I guess) less than 800 m above sea level. The type ssp. occurs in summer rainfall area, more than 900 - 1500mm per year, The southern distribution close to the ocean, very cold winters, the northern range closer to the tropics, so warmer temperatures throughout the year. Also much higher altitudes. The forms in the mid-range might get some snow in winter I know this does not say much about how they look, but might help in the way one treats them. Normally the epithet "nana" is used for a smaller form Christiaan