Because I came across them in The Seven Pillars of Wisdom
|Phosphorescent phantoms bloom, beautiful in the
impenetrable darkness of the desert, like faint,
fragile reflections of the impossibly bright, moonless, starlight.
Sweet, so sweet, their smell, dense and cloying, so that every
drawn breath of the brittle and chilled night air is
exquisite, sorbet sickly and sensuous.
Pale, ephemeral petals, siren semaphore for the
fertile flutter of their Lepidopteran lovers, flitting,
dusky Casanovas in a dance of scented seduction.
Ghost flowers, peripheral, and perceived, primarily
olfactorily as our camels pass sure footed, silent,
across the sands, scree and midnight efflorescence.
The picture used, of a night-blooming cereus is from Wikipedia, and has the following attribution line:
Aswin KP, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons