Page:An introduction to physiological and systematical botany (1st edition).djvu/108

78 scent in the course of the day, smell powerfully in an evening, whether the air be moist or dry, or whether they happen to be exposed to it or not. This is the property of some which Linnæus has elegantly called flores tristes, melancholy flowers, belonging to various tribes as discordant as possible, agreeing only in their nocturnal fragrance, which is peculiar, very similar and exquisitely delicious in all of them, and in the pale yellowish, greenish, or brownish tint of their flowers. Among these are ''Mesembryanthemum noctiflorum, Dill. Elth. t. 206, Pelargonium triste, Cornut. Canad. 110, and several species akin to it, Hesperis tristis, Curt. Mag. t. 730, Cheiranthus tristis, t. 729, Daphne pontica, Andrews's Repos. t. 73, Crassula odoratissima, t.'' 26, and many others. A few more, greatly resembling these in the green hue of their