Cactus Blossom

Night-blooming cereus is the common name for many flowering ceroid cacti that bloom at night. Selenicereus grandiflorus and Epiphyllum oxypetalum are among the cacti that may be called by this name. The flowers are almost always white or very pale shades of other colors, often large and frequently fragrant. Most open after nightfall, and most are wilting by dawn. The flowers are short-lived: in some species, such as Selenicereus grandiflorus, each flower blooms for only a single night.

Selenicereus grandiflorus is a cactus species originating from the Antilles, Mexico and Central America. The flowers are 17-22.5 cm long and reportedly as much as 38 cm wide. The cactus blooms at night because of its relationship with nocturnal pollinators, bats and moths. Its opalescent white petals reflect moonlight, which directs these pollinators toward the flower.

Epiphyllum oxypetalum has a native range from Mexico to Nicaragua. It blooms nocturnally, and its flowers wilt before dawn. The flowers are very fragrant and up to 30 cm long and 17 cm wide. Though it is sometimes called a night-blooming cereus, it is not closely related to any of the Cereeae species more commonly known by that name.

At full bloom, geraniol accounts for 72.54% of the total scent emission of Epiphyllum oxypetalum, followed by benzyl alcohol (12.96%) and methyl salicylate (3.75%). These scents predominantly originate from petals and sepals. Geraniol, benzyl alcohol and methyl salicylate are known to convey chemical signals between plants and insects, especially geraniol for hawk-moth. Moth-pollinated cacti emit complex blends of terpenoids and benzenoids during their transient nocturnal flowering.