Plant: Balloon Milkweed (Gomphocarpus physocarpus)

[flying cheetah]

Would be great if anyone could help me with the names of these flowers Maybe they are quiet common but I don't know much(or should I say nothing) about wild flowers in Africa I saw both in Imfolozi/KwaZuluNatal.
Would be helpful if I could get the scientific name as well Thanks a lot in advance!!

[hfglen]

Flying Cheetah,

2. is one of many milkweeds, most likely Gomphocarpus physocarpus.

[UNRHO]

This is also the food plant of the African Monarch butterfly (Danaus chrysippus aegyptius) larvae.

[lemonbalm]

hfglen is indeed correct - this is Gomphocarpus physocarpus. A similar species often encountered is Gomphocarpus fruticosus, which has creamy yellow flowers and the follicles (fruits) are tapered at the top. Most if not all milkweeds are utilised by the Monarch butterfly as food for their caterpillars - this is what makes the butterfly poisonous.