If you ask people on the street what their first association is with words as rose, fresia or hyacinth, nine out of ten will mention the fragrance of the flowers. Not allways the frangrance is considered as positive: 'to much' as with hyacinths or just simple unpleasant (Sauromatum venosum). More bulbous plants have frangrant flowers or plant parts, like Muscari armeniacum, Fritillaria imperalis and various Allium and Narcissus species or varieties, like N. 'Baby Moon' and 'Thalia'.
The bulb best known for its fragrance is Sauromatum venosum: a representative of the Araceae family. This plant flowers before the leaf is produced. A corm produces one, big finger shaped leaf on a long petiole. The petiole is brown-purple spotted at the bottom part. The inflorescence, a spadix, is typical for this family. The flowers grow in a spadix: the male flowers on top and the female flowers below. If you want to see the flower from a short distance, I would advise to do this before the individual flowers open. When they open, the flowers spread an awfull, pungent odour which can be decribed as rotting meat! It's not a flower for in a house, more for a greenhouse or a sunny place outside,
A less unpleasant odour is spread by the various Tulbaghia species. The best know species is Tulbaghia simmleri, with its drooping, pink coloured flowers in an umbel. The various plant parts hardly smell. If you break a leaf, root or the flowerstem you can smell a light onion like odour. Allium and Tulbaghia both belong the the Alliaceae. T. capensis has a more pungent odour: the roots, leaves, seeds and flowers have a onion like fragrance. The flowers of this species are brown-red coloured and the perianth segments are allmost completely grown together with spreading tips.
You can discuss about the fragrance of the flowers of Eucomis bicolor: pleasant or not. In my opinion the fragrance is unpleasant, it smells like rotting meat. In this case you would expect that the open flowers are covered with flies and other insects. This is the case with Eucomis autumnalis ssp. autumnalis, but not with E. bicolor. It seems that flies just love the star shaped, white flowers of E. autumnalis ssp. autumnalis. The flowers spread a light, slightly unpleasant odour, which is similar to E. bicolor.
You might think, are there no specialty bulbs with a more pleasant odour? Of course there are, take Albuca shawii for example. The flowerstem and leaves of this yellow flowering species from South Africa are covered with small hairs. IF you touch these hairs, they spread a pleasant, spicy odour. As far as I know Albuca shawii is one of the few Albuca species with fragrant plant parts.