Amaryllis belladonna (March Lily)

An alkaloid called lycorine (narcissine) in the bulb affects the heart and if the bulb is eaten in quantity, death can result. 

Ammocharis coranica (Ground Lily)

The bulb contains the following poisonous alkaloids: lycorine, acetylcaranine, caranine and crinamine.

Boophone disticha (Fan-leaved Boophone, Poison Bulb, Sore-eye Flower, Tumblehead)

The bulb contains poisonous alkaloids including lycorine and buphanine (resembling hyoscine) and consumption thereof can result in death.

Brunsvigia spp. (candelabra flowers)

The bulb contains poisonous alkaloids including: brunsvigine, brunsvinine, lycorine and crinamine. Levels of toxicity evidently differ seasonally.

Clivia miniata (Bush Lily, St John's Lily, Clivia, Fire Lily)

The entire plant is poisonous due to toxic alkaloids, mainly lycorine and cliviine. Death can result from eating it in large amounts.

Crinum spp.

Some species have poisonous seeds and bulbs, containing haemolytic saponin, and the alkaloids lycorine, crinine and crinamine.

Cyrtanthus  spp.

Bulb contains non-lethal haemolytic saponin and alkaloids, and causes vomiting and diarrhoea if eaten.

Haemanthus coccineus (April Fool, Blood Flower)

The bulb contains toxic alkaloids, including haemanthidine and haemanthamine, lethal if consumed in quantity.

Hymenocallis (spider lilies)

Bulbs contain the toxic alkaloid lycorine.

Narcissus spp. (daffodils and jonquils)

Bulbs and leaves cause severe vomiting and diarrhoea. Sap can cause dermatitis.

Nerine spp.

Bulbs contain poisonous alkaloids, but not usually enough to cause death if eaten.

Scadoxus spp.

Bulbs can contain toxic alkaloids.

Zephyranthes spp. (Zephyr lilies)

Bulb is toxic.