I grew these (Clivia miniata) commercially for a number of years and
until fairly recently was breeding them to produce pure ivory
flowers. I've also grown both true Amaryllis (belladonna - the hardy
species) and still grown several false 'Amaryllis' more correctly
known as Hippeastrum. There's only a remote similarity in the flowers
and apart from Clivia being a member of the Amaryllidaceae, I can't
understand how it should be mistaken for other Amaryllids.

As to cultivation, Clivias require bright, but indirect light and
during the main growing period (from flowering till late autumn)
should be kept moderately moist. Direct sun wll burn the foliage
making it very unsightly and since these are evergreen, you will have
to live with damaged leaves for a good year or so. They appreciate
regular feeding when in active growth and an application of dilute
Miracle Gro every 2 weeks from flowering until autumn will keep them
hale and hearty.

Whilst they have a reputation for enjoying cramped conditions at the
root, they grow better if potted on every other year immediately after
flowering. A sharply drained, loam-inclusive compost gives best
results and I've always used a 50/50 mix of JI No2 and multi-purpose
compost to which 20% by volume either perlite or horticultural grit
has been added. From late autumn until the appearance of the flower
spike, Clivias are best rested in a bright cool, but frost-free
position and only given enough moisture to prevent the compost
becoming absolutely dust dry. Cool, nearly dry winter rests help
initiate the development of the flower buds and ensures a good show in
spring.