Marrows have long trailing stems that sprawl across the ground with large deeply lobed mid green hairy leaves and produce bright yellow, five petalled, open faced flowers.
The fruits grow from the base of the flower into elongated smooth skinned shapes in colours of mottled green and cream.
If picked young they are courgettes, if left to grow to full size they are vegetable marrows - both are delicious with a little butter and freshly ground pepper.
Beware though that they need a lot of room, or they will just climb all over your other vegetables, depriving them of nourishing sunlight.