OPENING OF THE PASSAGE TO THE INTERIOR OF THE FLOWER. 



213 



The number of hours during which these flowers remain open are as follows: — 



Hours. 



Hibiscus Trionum 3 



Calandrinia compressa 4 



Portulaca oleracea 5 



Drosera longifolia 5 



Arenaria rubra 5 



Spergula, arve nsis 5 



Cereiis nycticalus 5 



Hours. 



Sisyrinchium anceps 5 



Roemeria v iolacea 6 



Oxalis striata 7 



Mirabilis longißora 7 



Cereus grandißorus 7 



A llionia violacea 8 



Erodium Cioutarium 8 



Hours. 



Iris arenaria 9 



Convolvidus tricolor 10 



Tradescantia Virginica 10 



Portulaca grandiflora 10 



Cistus creticus 12 



Hemerocallis fulva 14 



From these tables we see that plants with ephemeral flowers may be arranged in 

 two groups; those in which the flowers open between early morning and noon, and 

 those which open at the commencement of twilight or during the night. The latter 

 may be distinguished as " night-flowerers ". 



Included with the ephemeral flowers are such as open in the evening between 

 seven and eight o'clock, and remain open the whole night and following morning till 

 past midday, or even till evening. For the most part, these close within twenty- 

 four hours of their opening. To these belong several species of Thorn-apple 

 and Evening Primrose, Morina, the Marvel of Peru, and a few Cactuses {Datura 

 Metel and Stramonium, (Enothera biennis and grandiflora, Morina Persica, 

 Mirabilis Jalapa, Echinocactus Tetani). 



Another series of plants have the peculiarity that their flowers open for the first 

 time during the morning, close at evening, and open again the following morning, 

 but fade or fall during the afternoon of the second day. Examples are many: 

 Papaveracese, many species of Flax, the Raspberry, a few Cinquefoils and Cactuses 

 (Glaucium corniculatum and luteum, Papaver alpinum, Linum tenuifolium, 

 Ruhus Idceus, Potentilla recta, and Opuntia nana). 



The duration of flowering (i.e. period of persistence of single flowers) in plants 

 which keep open for more than a single day is indicated, for selected examples, in 

 the annexed table: — 



2 Days. 



Centuncidtis minimus. 

 Dianthus prolifer. 

 Epilobium collinum. 

 Geranium pratense. 

 Papaver somniferum. 

 Potentilla atrosanguinea, &c. 

 Rosa arvensis, &c. 

 Saponaria Vaccaria. 

 Sinapis arvensis. 

 Veronica aphylla, &c. 



3 Days. 



Lonicera Caprifolium. 

 Potentilla formosa. 

 Agrimonia Evpatorium. 

 Aphyllanthes monspeliensis. 

 Galium infestum, &c. 

 Helianthoiium alpestre, &c. 



4 Days. 



Lychnis diurna. 

 Sagina saxatilis. 

 Sedum atratum. 

 Scilla liliohyacinthus. 

 Telephium Imperati. 

 Sanguinaria Canadensis. 



5 Days. 



Eschscholtzia Californica. 

 Fritillaria meleagris. 

 Scilla Sibirica. 

 Erytkrcea Centaurinm. 

 Linum viscosum. 



6 Days. 



Digitalis purpurea. 

 Erythrcea pulchella. 

 Hemerocallis flava. 



Lilium, album. 

 Oxalis lasiandra. 



7 Days. 



Ranuncidus acer, &c. 

 Pelargonium zonale, &c. 



8 Days. 



Eranthis hiemalis. 

 Hepatica triloba. 

 Parnassia palustris. 

 Saxifraga bryoides. 



10 Days. 



Cyclamen Europceum. 



12 Days. 



Crocus satirus. 

 Saxifraga Burseriana. 



