Begonia rex 'Escargot'
Aloe polyphylla (there are also some with more distinct spiral-formations)
Turbina corymbosa:
Tabernaemontana pandacaqui- flower:
Corkscrew vine (Vigna caracalla):
http://www.geo.de/reisen/community/bild/354514/Malaga-Spanien-Schneckenbohne