156 PLANTS OF THE ALPINE MEADOWS 



yet fully understood. No doubt the plants are 

 thereby rendered extremely conspicuous to butterflies, 

 by which they are often fertilised, though it is 

 possible that self-fertilisation is the rule. In the case 

 of the Autumn Saffron, which we shall shortly discuss, 

 the colour has become " fixed " or constant, and this 

 would appear at first sight just as effective as an 

 insect advertisement. However, it does not appear 

 that the manner of fertilisation of the Saffron flowers 

 is known with certainty at present. 



THE VIVIPAROUS POLYGONUM. 



The Viviparous Polygonum (Polygonum mviparum, 

 Linn., natural order Polygonacese, the Dock family), is 

 a very frequent plant in the Alpine meadows. 

 Everyone is familiar with the beautiful pink spikes 

 of flowers of its near relative the Bistort, Polygonum 

 Ustorta, Linn., which is a much more conspicuous 

 plant, often contributing largely to the colour scheme 

 of the meadows. The Viviparous Polygonum (Plate 

 XXXV., Fig. 2) is easily recognised by the slender 

 flower-spike, partly composed of small white or flesh- 

 coloured flowers in the higher portion, and numerous 

 little red "bulbils" below. 



These "bulbils" are not flowers, though they 

 occupy the position of flowers. They are really little 

 buds minute leafy shoots which become detached 

 from the spike and fall to the ground. They root 

 themselves to the soil, and grow into new plants. 

 Thus, should the Viviparous Bistort fail to produce 



