Tropaeolum majus comes from South America, from the Andean foothills from Bolivia to Columbia, and has been grown in Britain since around 1686. It naturally has orange flowers, as in the top photo here, and grows in the wild as a climber, with prehensile leaf stalks (petioles). Successive cycles of selection and possibly hybridisation produced numerous varieties including dwarf, compact (Tom Thumb) forms and double cultivars that were popular in Victorian and Edwardian Britain. Today it's almost always raised from seed but in the 19th. century numerous named varieties were bred and propagated from cuttings that were overwintered in heated greenhouses, and were said by William Robinson, in his English Flower Garden, to produce more flowers and fewer leaves if grown in this way.
There are various accounts as to how the plant acquired its generic name. All say that Tropaeolum owes its name to the martial connotations of its shield-like leaves and helmet-like flower shape, but there are differing opinions on whether the name was derived from Greek or Latin. In Roman times a tropeum was a trophy pole used to display the armour and helmets of vanquished enemies, and some say Linnaeus consequently used the derived name Tropaeolum for the genus, recognising that the leaves resembled shields and the flower, when tilted downwards, looked like an elaborate helmet. Others say that Linnaeus derived the generic name from the Greek tropaion, meaning a trophy, for essentially the same reason
Nasturtium nectar is hidden deep inside the long spur (see top photo) formed from the sepals and long-tongued insects have to force their way into the mouth of the flower to reach it, although I have seen bumblebees that have learned to go around to the back of the flower and bit through the nectar spur to reach the nectar. John Gerard, in his General Historie of Plantes, mentions that these flowers were also known as lark's heel, on account of the spur that resembles the claw on a lark's foot.