Neither is the scent of flowers equally strong and agreeable at all hours of the day: many, even of our indigenous flowers, have the strongest scent at night. The _Ixia cinnamomea_ gives out its fragrance in the evening only; the highly-scented Lesser Orpine (_Crassula odoratissima_) only in the night; the _Epidendrum fragrans_, morning and evening; another species of Epidendrum, hung up in a room, without earth or water, yields an agreeable perfume for years. The flowers of the _Hebenstreitia dentata_ are scentless in the morning, have a disagreeable smell at noon, and give out in the evening a fragrant odour, not unlike that of the Hyacinth. These properties of flowers, and the opening and shutting of many at particular times of the day, led to the idea of planting them in such a manner as to indicate the succession of the hours, and to make them supply the place of a watch or clock. Those who are disposed to try the experiment may easily compose such a dial by consulting the following table, comprehending the hours between three in the morning and eight in the evening. +-------------------------------------------+--------+---------+ | Names of Plants. |Hours of|Hours of | | |Opening.|Shutting.| +-------------------------------------------+--------+---------+ |Yellow Goat’s Beard (_Tragopogon | | | | luteum_) | 3 | | | | | | |Common Base Hawkweed, (_Crepis | | | | tectorum_) | 4 | | | | | | |Field Sowthistle, (_Sonchus agrestis_) | 5 | | | | | | |Dandelion (_Leontodon Taraxacum_) | 5 | | | | | | |Alpine Base Hawkweed, (_Crepis | | | | alpina_) | 5 | | | | | | |Naked-stalked Poppy (_Papaver | | | | nudicaule_) | 5 | | | | | | |Orange Day-lily (_Hemerocallis fulva_) | 5 | | | | | | |Red Hawkweed (_Hieracium rubrum_) | 5-6 | | | | | | |Meadow Goshmore (_Hypochæris | | | | pratensis_) | 6 | | | | | | |Red Base Hawkweed, (_Crepis rubra_) | 6-1/2 | | | | | |