Here's my list, seeds can be swaped with people from any country.
Cleistocactus strausii
Cereus jamacaru (habitat data)
Cereus fernambucencis (habitat data)
Echinopsis "lua" (a hybrid similar to E. subdenudata, see the picture I took of the motherplants here: download/file.php?id=30723 )
Echinopsis subdenudata
Echinocactus grusonii
Ferocactus herrerae 1 (with short spines)
Ferocactus herrerae 2 (with longer spines)
Ferocactus latispinus
Gymnocalycium mihanovichii (?) (not sure about the species, but has white flower)
Harrisia adscendens (habitat data)
Mammillaria polythele var. inermis
Mammillaria polythele
Mammillaria polythele var. durispina
Mammillaria mammillaris
Mammillaria nivosa
Mammillaria haageana
Mammillaria karwinskiana subsp. karwinskiana
Melocactus matanzanus
Melocactus ernestii (habitat data)
Melocactus zehntneri (habitat data)
Melocactus violaceus (habitat data)
Notocactus haselbergii
Opuntia stricta var. dilenii
Pilosocereus gounellei (habitat data)
Pilosocereus chrysostele (habitat data)
Pilosocereus catingicola subsp. salvadorensis (habitat data)
Pilosocereus spec. (a robust pilosocereus, 4 m high, stems with 12 cm of diameter, with habitat data)
Pilosocereus "seedmix" (seeds of mixed Pilosocereus: P.magnificus, P. glauchochrous, P.chrysostele)
Tacinga spec. (small cladodes, not many spines)
Tacinga inamoena (habitat data)