Adding photos of semps that I have (now only a very small fraction of what I used to have), I added each of these to the database as plants I'm willing to trade with
Four views of a small concrete trough that has:
1. S. 'Alluring', an interesting little creature with small ball-shaped rosettes with dark tips, in summer opening up into small "roses".
2. S. arachnoideum 'Robin' - showy red rosettes in spring, always looks good
3. S. Sempervivum marmoreum subsp. erythraeum, one of my very favorite species (got it as just S. erythraeum many years ago) before the name change, great for planters because of slow growth & unique leaf build, lovely soft pinkish tones in spring.
In the photos, you can see a pad of eastern USA native Opuntia humifusa, staying very slow and contained in my trough filled with almost sterile medium (mostly sand/grit).
Photo from early April 2010, very dark rosettes of 'Alluring' on the left. Note, it doesn't make tight colonies, the stolons are long, I sometimes pin them to infill blank spots. In lower center is arachnoideum 'Robin', and erythraeum above.
Close-up of S. 'Alluring' late April 2013.
Late May 2017, everything looking pretty good, 'Alluring' on left, arach 'Robin' in center, erythraeum above.
First week of July 2010, same line-up left to right, 'Alluring', 'Robin', erythraeum.