a)
enzymes convert DMT from phalaris to 5MeO-DMT (no fun), so using freshly harvested plant material is the choice, you need a lot of it, !!!3 plants!!!, approx. mass 5 g (.060% alkaloida content)
b)
UTFSE/Erowid/Lycaeum/Google
c)
Acacia spp. (Maiden's Wattle)
Anadenanthera spp. (Yopo)
Desmanthus illinoensis (Bundle Flower)
Phalaris Grass (Reed Canary Grass)
Psychotria viridis
Mimosa hostilis (Jurema)
Virola spp. (EpeƱa)
Arundo donax (Giant River Reed)
Diplopterys cabrerana (Chagro-panga
and many others!