CONSPICUOUSNESS OF FLOWERS 83 
Reference has already been made (p. 72) to the various ways in which the 
pollen of anemophilous plants is protected. 
lowers employ many methods of enticing insects suitable for transferring pollen :— 
colour and odour, the proffer of pollen and nectar, provision of a shelter, &c. 
It is the pefals or pertanth-leaves which, owing to their bright colours, play 
the leading part in bringing about Conspicuousness in flowers, and in enticing 
cross-pollinating insects to visit them. If one side of the corolla is not visible 
to insects on the wing, it is less brightly coloured than the side which they are able 
tosee. In species of Gagea (G. pratensis, arvensis, sylvatica, and others), for instance, 
the perianth leaves which are spread out like a star in the sunlight, are shining yellow 
on their inner side, while externally they are of a dull yellow, which is rendered 
even less conspicuous by a green dorsal stripe. The opposite is true for urceolate 
or campanulate flowers, such as those of species of Campanula, for in these the 
inner side, which is not seen by insects during flight, is less conspicuous than 
the outer which is exposed to their view as they wander about in quest of food. 
When the petals are modified into nectaries, or have not been fully developed for 
other reasons, the sepfa/s in many cases take over the function that more properly belongs 
to the petals. This is a very common occurrence, and it may suffice to mention here 
some Ranunculaceae, such as Anemone nemorosa and ranunculoides, Hepatica friloba, 
Trollius europaeus, Eranthis hyemalis, Pulsatilla pratensis, Aconitum Napellus, &c. 
The petals are frequently helped by the sepals in the work of allurement, so 
that the two outermost whorls of the flower minister to the same end. The 
inner side of the sepals in Nymphaea alba, for instance, which is turned towards - 
the air and light, is coloured white like the petals, while the under side that lies 
upon the water and is not visible from above, has a green colour. The inner 
side of the sepals of Comarum palustre is coloured a dark purple brown, so that 
the flower is made much more conspicuous, for though the petals are similarly 
coloured, they are only about a third of the size of the sepals. 
More rarely the s/amens serve as a means of allurement. The willows may 
be cited as the best known examples, their yellow or red anthers enticing numerous 
insects to visit them. Sometimes filaments are of a bright colour. In species of the 
genus Verbascum, they possess a covering of violet, purple, yellow, or whitish hairs, 
which is often very conspicuous. Even in the case of Thalictrum aquilegifolium, 
and Plantago media, which are anemophilous, the filaments are coloured violet. 
(Cf. p. 69, note.) 
Still more rarely do the carpels play the part of alluring agents, e. g., in Caltha 
palustris and Comarum palustre. 
It more frequently ‘happens that flowers or inflorescences are made more 
conspicuous by coloured Jdracts, e.g. the purple bracts of Melampyrum arvense, 
the azure-blue ones of M. nemorosum, and the blue involucre under the capitulate 
umbels of species of Eryngium, in which even the stalk of the inflorescence is 
of a bright blue colour. 
By the association of several or many flowers in an inflorescence, it is frequently 
brought about that even small flowers are rendered sufficiently conspicuous. The 
florets of the Compositae, for example, together form inflorescences that are visible 
from afar, with the result that these plants receive more insect-visits than any 
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