Stinking iris Iris foetidissima has two memorable features. The first is the vibrant orange seeds that are revealed when the seed pod bursts open. These make excellent decorations and I have a vase of them on my desk as I write.
Each seed is surrounded by a soft orange aril, which slowly dries and wrinkles once it's exposed to air.
The other memorable feature isn't the flower, which is unspectacular by the standards of many irises, but the smell. If you crush the foliage between finger and thumb you release an aroma that's reminiscent of roast beef or, perhaps more accurately, the exaggerated beefy smell of a packet of roast beef-flavoured crisps. The species is sometimes known as roast beef plant.
Iris foetidissima is easy to grow from seed and thrives on a dry, sunny bank in my garden, producing seed pods for winter decoration every year.