Lilies (broad sense)

Nearly all are six-'petalled' flowers (actually three petals and three sepals), often bell-shaped (actually placed in several different families):
Amaryllidaceae for Agapanthus, Allium, Amaryllis, Crinum, Galanthus, Leucojum, Narcissus, Nothoscordum, Sternbergia, Tetrastagma, Tristagma
Asparagaceae for Agave, Asparagus, Camassia, Convallaria, Cordyline, Hyacinthoides, Hyacinthus, Muscari, Ornithogallum, Polygonatum, Ruscus, Scilla, Yucca
Colchicaceae for Colchicum
Commelinaceae for Commelina and Tradescantia
Iridaceae for Crocosmia, Crocus, Gladiolus, Iris, Romulea, Sisyrinchium,
Liliaceae for Erythronium, Fritillaria, Gagea, Lilium, Tulipa
Melanthiaceae for Herb Paris and Veratrum
Nartheciaceae for Narthecium
Tofieldiaceae for Tofieldia
Xanthorrhoeaceae for Kniphofia

Choose by flower colour:


'Lilies' - blue, mauve or purple

Hyacinthoides
Muscari
Hyacinthus
Crocus tommasinianus
Bluebells
Grape-hyacinth
Hyacinth
Crocus
Camassia leichtlinii
Romulea columnae
Iris
Sisyrinchium bermudiana
Camassia leichtlinii
Sand Crocus
Iris
Blue-eyed-grass
Scilla autumnalis
Scilla verna
Scilla siberica
Scilla peruviana
Autumn Squill
Spring Squill
Blue Squill
Portuguese Squill
Scilla forbesii
Colchicum autumnale
Crocus
Agapanthus
Chionodoxa
Colchicum
Crocus
Agapanthus

'Lilies' - pink or red

Lilium martagon
Fritillaria
Fritillaria
Allium
Martagon Lily
Snake's-head Fritillary
Snake's-head Fritillary
Alliums
Gladiolus communis
Kniphofia
Crinum
Amaryllis
Gladiolus
Red-hot-poker
Cape Lily
Jersey Lily
Nerine
Crocosmia
Tulipa
Guernsey Lily
Crocosmia
Tulip

'Lilies' - white

Alliums
Ornithogallum umbellatum
Tristagma uniflorum
Yucca
Garlics
Garden Star-of-Bethlehem
Ipheon
Yucca
Galanthus nivalis
Leucojum aestivum
Polygonatum multiflorum
Convallaria majalis
Snowdrop
Summer Snowflake
Solomon's-seal
Lily-of-the-valley

Cordyline australis
Gladiolus callianthus
Hyacinthoides hispanica??
Narcissus poeticus
Cabbage-palm
Abyssinian Gladiolus
Spanish Bluebell?
Pheasant's-eye

'Lilies' - Orange, yellow or green

Gagea lutea
Narthecium ossifragum
Tofieldia pusilla
Ruscus aculeatus
Yellow Star-of-bethlehem
Bog Asphodel
Scottish Asphodel
Butcher's-broom
Narcissus pseudonarcissus
Narcissus bulbocodium
Narcissus jonquilla
Paris quadrifolia
Daffodil
Hooped Petticoat
Jonquil
Herb-Paris
Iris pseudacorus
Crocus crysanthus
Sternbergia
Asparagus officinalis
Flag Iris
Crocus
Winter Daffodil
Asparagus-fern
L. pyrenaicum
Alstroemeria
Kniphofia
Montbretia
Pyrenean Lily
Peruvian Lily
Red-hot poker
Montbretia