You got me!!! I had really wished for a bonsai speciosum lol.
There are basically about 6 or 7 geographical forms of speciosum although genetic analysis suggests only 2 subspecies at most. This comes from a website of Gerry Walsh better Know as the Rocklily Man.
This is his site, TheRockLilyMan – You've found the home page of Gerry Walsh
full of great info and photos, including lots of in situ photos.
The most northern form var. pedunculatum and an inland for var blackdownense have small growths and are mature at a size similar to the one in Bertholt's first photo. These 2 grow in hot seasonally arid rocky outcrops that even cacti would struggle to survive on. Even the southern form, speciosum, often is found on rocky outcrops subject to heat, drought and bushfires. This is what makes them a challenge to grow in a cooler climate. I grow mine outside under 50% shade and don't water them in winter until they start to shrivel. The one on my driveway grow in full sun most of the day and have survived that in 48deg C. We get a few days each year in the 40-45degC. range and this does not cause any damage or leaf-burn to mature plants if they are acclimatized.
Speciosums are now being bred that have the short growths of blackdownense and the flower size, color and shape of the larger varieties