Hovering over the green text will display an illustration of the plant or trait concerned.
The key to the dissected flower images is here.
1 a Distribution China 2
b Distribution Japan 6
2 a Stems 1.5 - 3+ m. Leaves spread regularly up the stem, bunching in the middle. 10 - 30+ flowers. Flower bracts lost before flower is fully open. Flowers show no zygomorphism. 3
b Stems 0.5 - 1.5m. Leaves not spread regularly up the stem. 3 - 20 flowers. Flowers retain the lower flower bract for some time after opening. Flowers show slight to pronounced zygomorphism about a horizontal plane. Cardiocrinum cathayanum .
3 a Stems green, robust. Flowers have a green tinge, which becomes cream in full sun, with slight to medium prounced bands of magenta on the adaxial surfaces of the sepals and petals and faint colour on the abaxial surface of the petals. Never white. The corolla is not divided. Cardiocrinum giganteum v. giganteum
b Stems darker green, sometimes streaked with or completely purple, more gracile. Flowers white with no or a slight green tinge. Corolla is divided on mature flowers. 4
4 a Flowers are white with slight to strong bands of magenta mainly on the adaxial surfaces of the sepals and petals but some on the abaxial surface of the petals. Cardiocrinum giganteum v. yunnanense
b Petals are a uniform colour abaxially and adaxially, either white or magenta. 5
5 a Flowers are white with no trace of of magenta. Cardiocrinum giganteum v. yunnanense f. alba . 
b Flowers are completely magenta with no white. Cardiocrinum giganteum v. yunnanense . Far Reaches Farm refer to their 'rosea' cultivar as 'Big and Pink'.
6 Leaves not spread regularly up the stem. 3 - 20 flowers. Flowers retain the lower flower bract for some time after opening. Flowers show slight to pronounced zygomorphism about a horizontal plane.
a Stem usually 0.5 - 1.25m. Few flowers, (3 - 7) Cardiocrinum cordatum cordatum .
b Tall, more robust stem to 1.75m. Up to 20 flowers. Cardiocrinum cordatum s.sp. glehnii
See The Genus Cardiocrinum, its Identification and Cultivation, p.32 for a text version of this key.