366 



HUTCHINSON'S POPULAR BOTANY 



FIG. 448. FLOWER OF 

 HORSE CHESTNUT. 



Hermaphrodite or complete flower 

 with stamens and pistil. 



has evaporated, and that this is the signal for the 

 closing of many flowers ; but it may be doubted 

 whether these circumstances stand in the relation 

 of cause and effect. Flowers open and close at 

 almost all times of the day and night ; and though 

 in some cases the periods of their opening have 

 distinct reference to the visits of bidden guests, 

 it seems extremely doubtful that the periods of 

 their closing have any reference to unbidden ones. 

 Be that as it may, the phenomena of the open- 

 ing and closing of flowers are full of interest, 

 and as the subject has been named, we will offer 

 a few remarks upon it before passing on. 



It is well known that Linnaeus devised a floral dock at Upsala, by 

 grouping together plants according to the hours at which they open and 

 close, and that for a time the growing of these flower-clocks in public 

 and private gardens became quite a rage. In recent years Kerner has 

 repeated the experiment at Innsbruck (47 N. lat.), and a comparison of 

 his tables with those of the older naturalist has shown that flowers both 

 open and close earlier in the day at Upsala than at the more southerly 

 situated Innsbruck. " The result," he says, " especially the earlier opening, 

 is probably connected with the fact that the sun during the flowering 

 season of the plants in question rises about an hour and a half earlier 

 at Upsala than at Innsbruck." 



Of the flowers in Linnaeus' clock the earliest to open was the Goatsbeard 

 (Tragopogon pratensis^ fig. 446), a Composite flower like a large Dandelion, 

 which has received in this country the name of John-go-to-bed-at-noon, 

 from its habit of closing about midday. 



Broad o'er its imbricated cup 

 The Goatsbeard spreads its saffron rays, 



But shuts its cautious florets up, 

 Retiring from the noontide blaze. 



Owing to its very early opening it has been 

 pollinated usually long before noon ; and as soon 

 as a flower has been pollinated it either begins 

 to close, changes colour, or casts off its now useless 

 non-essential organs. The latest flower to open 

 was the magnificent Queen of the Night, which 

 unfolded its scentless white petals two hours 

 before midnight. 



We approach now a new and more important 

 division of the subject namely, the means by 

 which the pollen of flowers is conveyed to the 



FIG. 449. SECTION OF HORSE 

 CHESTNUT, MALE FLOWER. 



(ov) Rudimentary ovary. There is 

 no style or stigma. 



