8 1 WAYSIDE AND WOODLAND BLOSSOMS. 



stamens. The anthers are dark purple, and open in such 

 manner that the pollen falls between them and the pistil, some- 

 what as in Viola. By this arrangement both honey and pollen 

 are protected from the depredations of insects who have no 

 right to it. Bees, however, in forcing their tongues down to 

 the honeyed ovary, separate the anthers and let loose the 

 pollen, which falls upon their heads and will be brought into 

 contact with the stigma of another flower at their next visit. 

 Cross-fertilization is further helped by the stigmas of a flower 

 not becoming ripe until its anthers have shed their pollen. 

 Flowers June and July. 



Name probably from the Latin Bourra, a flock of wool, in 

 allusion to its hairy character. 



Oblong Pond- weed (Potamogeton polygonifolius). 



We have pond-weeds in abundance, but the Potamogetons 

 are the pond-weeds par excellence. There is scarcely a piece 

 of water in this country, be it river, lake, pond, canal, or inter- 

 mittently dry ditch, but has one or more species growing there. 

 The genus is a very difficult one, such as it is impossible to do 

 more than show the general characters of here. Hooker and 

 Bennett, in their revision of the genus, give twenty-one British 

 species with a number of connecting sub-species and varieties. 

 The one figured here is the Oblong Pond-weed (P. polygoni- 

 folius] , with narrowly egg-shaped floating leaves, and narrower 

 submerged leaves. All have long leaf-stalks. The floating leaves 

 always present the upper side to the air, and are always perfectly 

 dry. The flowers are greenish and unattractive, collected into a 

 slender spike. Individually they consist of a four-parted peri- 

 anth, four stamens, four carpels. There is a species (P. natans) 

 with broader floating leaves and narrow submerged leaves. A 

 broader still is P. plantagineus , with clearer leaves and more 

 slender leaf-stalks. P. crispus, P. densus, P. perfoliatus^ P. 



