As far as I know, mine is a tropical form. Indeed, some seeds did germinate the last time I sowed them without any special treatment.
Having said that, after my exams, I will try the following growing conditions to see what works best:
1. Startify seeds for 4 weeks
2. Put pot with seeds in full sun, covered with plastic
3. Same as 2, except in shade.
My d.aliciae has germinated but all have died! They just turned brown!! I have had best growing rates from D.dielsiana, D.nidiformis (sp?), D.spah and one Cuban ssp.