II SCROPHULARIACE.E 321 



P. sylvatica. — This curious flower is unsymmetrical 

 and compressed laterally. The corolla-tube is 10-14 

 mm. in length. The under lip falls from right to left, 

 so that the right half is 2-8 mm. higher than the left. 

 The tube is contracted about 1 mm. below the opening 

 and then expands again, so that it consists of a very 

 short and a longer lower part connected by a very narrow 

 passage. The stigma projects slightly, as usual. The 

 anthers are arranged so as to form a pollen-box, and 

 the lower edges are fringed with long hairs which direct 

 the pollen on to the bee. The edges of the upper lip of 

 the corolla are rolled back, and the inner edge is armed 

 with projecting teeth. The plant is glabrous. 



P. palustris. — The corolla-tube is rather shorter than 

 in the last species, and the anthers have not the lower 

 fringe of long hairs, which H. Miiller suggests are not 

 in this case required, because the anthers are so close to 

 the bee's head that the pollen needs no guidance. The 

 plant is an annual, and glabrous or sparingly hairy. 



Euphrasia (Eye-bright) 



This genus is semi-parasitic on the roots of grasses. 

 The suckers are tiny little nodules which only just pene- 

 trate into the root of the host. Euphrasia is an annual, 

 and Kerner makes the interesting suggestion ' that the 

 useful substances existing in the green leaves of the 

 Eye-bright may, before it withers, be transferred to the 

 host plant. If so, then it would be unjust to Euphrasia 

 to call it a parasite, for the two plants would be mutu- 

 ally beneficial, as occurs in other cases (see p. 217). 

 Dichogamous, generally protogynous bee flowers, with 

 concealed nectar, secreted by the lower part of the 

 ovary. This is one of the genera with reference to the 

 species of which there has been much difi'erence of 

 opinion. Bentham and Hooker consider that there is 

 probably but one in the northern hemisphere. AVett- 

 stein, in a recent memoir,^ makes about fifty, fourteen 



■' Nat. Hist, of Plants, vol. i. 

 ^ MonographiK der Gattung Euphrasia. Leipzig, 1896. 



Y 



