OPENING OF THE PASSAGE TO THE INTERIOR OP THE FLOWER. 



213 



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



Hours. 



Hibiscus Triomim 3 



Calandrinia compressa 4 



Portulaoa oleracea 5 



Drosera longifolia 5 



Arenaria rubra 5 



Spergula arvensis 5 



Cereus nycticaliis 5 



HOUIB. 



Sisyrinchium anceps 5 



Roemeria violacea 6 



Oxalis striata V 



Mirabilis longifiora 7 



Cereus grandijlorus 7 



Allionia violacea 8 



Erodium Cicutarium 8 



Hours. 

 Iris arenaria 9 



Convolvulus tricolor. 10 



Tradescantia Virginica 10 



Portulaoa 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 Stramonivmi, CEnothera biennis and grandifiora, Morina Persica, 

 Mirabilis Jala/pa, 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 Easpberry, a few Cinquefoils and Cactuses 

 (Glaucium corniculatum and lutewm, Papaver al/pinwm, Linura tenuifolium, 

 Rubus IdcBus, Potentilla recta, and Opuntia nanJa). 



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. 



Centunculus minimus. 

 Dianthus prolifer. 

 Epilobium collinum. 

 Geranium praiense. 

 Papaver somniferum. 

 Potentilla atrosanguinea, &c. 

 Rosa arvensis, &c. 

 Saponaria Vaccaria. 

 Sinapis arvensis. 

 Veronica aphylla, &c. 



3 Days. 



Lonicera Caprifolium. 

 Potentilla formosa. 

 Agrimonia Eupatorium. 

 Aphyllanthes monspeliensis. 

 Qalium infestum, &c. 

 Helianthemum alpestre, &c. 



4 Days. 



Lychnis diwrna. 

 Sagina saxatilis. 

 Sedum atratum. 

 Scilla liliohyacinthus. 

 Telephiimi Imperati. 

 Sanguinaria Canadensis. 



5 Days. 



Eschscholizia Califomica. 

 Fritillaria meleagris. 

 Scilla Sibirioa. 

 Erythrcea Cen.taimu/m, 

 lAnum viscosum. 



6 Days. 



s pv/rpurea. 

 Erythrcea pvlohella. 

 Hemerocallis flava. 



lAlium album. 

 Oxalis lasiandra. 



7 Days. 



Ranunculus acer, &c. 

 Pela/rgonium zonale, &c. 



8 Days. 



Eranthis hiemalis. 

 Hepatica triloba. 

 Pa/rnassia palustris. 

 Saxifraga bryoides. 



10 Days. 



Cyclamen Europceum. 



12 Days. 



Crocus sativus. 

 Saxifraga Burseriana. 



