i8o 



THE REPRODUCTIVE ORGANS 



(about three hundred). Each has an inferior ovary, and 

 above it is the calyx, consisting of a whorl of hairs. Such 

 a calyx is said to be pappose. Within this is the ligulate 

 corolla. The style has a two-lobed stigma, and also a brush 

 of hairs, which, however, is of no use, as these florets have 

 no stamens, i. e. they are all pistillate ; no honey is secreted, 

 and they are ripe before the inner florets. About forty 

 tubular flowers will be found in the centre, differing 

 from the outer ones as follows: they are smaller and 

 less attractive ; the corolla is tubular and five-toothed ; 



Fig. 123. Florets of Coltsfoot. i, ligulate, female ray-floret; 

 2, tubular, male disk-floret ; Pa, pappus ; ov, ovary. 



at the base, honey is secreted ; the ovule in the ovary 

 is abortive ; there are five stamens with joined anthers, 

 and the style has a pollen-brush, but not a functional 

 stigma. As the outer female florets are ripe before the inner 

 male ones, self-pollination cannot take place ; they are 

 therefore dependent on insect-visits. The chances of pol- 

 lination are increased by the prolonged flowering-period. 



The Dandelion. Compare the flower-head of the Dande- 

 lion (Fig. 104) with those of the Daisy and Coltsfoot, and 

 notice that the hollow stalk is devoid of leaves. 1 The 



1 All parts of the plant contain a milky juice or latex, a fluid 

 which consists partly of waste substances, and to some extent of 

 nutritive materials. The latex is contained in irregular channels 

 known as laticiferous vessels. 



