_Cerea._ l. 15. Cactus grandiflorus, or Cereus. Twenty males, one female. This flower is a native of Jamaica and Veracrux. It expands a most exquisitely beautiful corol, and emits a most fragrant odour for a few hours in the night, and then closes to open no more. The flower is nearly a foot in diameter; the inside of the calyx of a splendid yellow, and the numerous petals of a pure white: it begins to open about seven or eight o'clock in the evening, and closes before sun-rise in the morning. Martyn's Letters, p. 294. The Cistus labdiniferus, and many other flowers, lose their petals after having been a few hours expanded in the day-time; for in these plants the stigma is soon impregnated by the numerous anthers: in many flowers of the Cistus lubdiniferus I observed two or three of the stamens were perpetually bent into contact with the pistil. The Nyctanthes, called Arabian Jasmine, is another flower, which expands a beautiful corol, and gives out a most delicate perfume during the night, and not in the day, in its native country, whence its name; botanical philosophers have not yet explained this wonderful property; perhaps the plant sleeps during the day as some animals do; and its odoriferous glands only emit their fragrance during the expansion of the petals; that is, during its waking hours: the Geranium triste has the same property of giving up its fragrance only in the night. The flowers of the Cucurbita lagenaria are said to close when the sun shines upon them. In our climate many flowers, as tragopogon, and hibiscus, close their flowers before the hottest part of the day comes on; and the flowers of some species of cucubalus, and Silene, viscous campion, are closed all day; but when the sun leaves them they expand, and emit a very agreeable scent; whence such plants are termed noctiflora.]