110 BRITISH FLOWERING PLANTS chap. 



S. acaulis is tricecious. It is richly visited by 

 insects. 



S. Otites, on the contrary, is said to be generally 

 wind-fertilised. The flowers are yellowish green, small, 

 and numerous. They are dicEcious, the male flowers 

 being the more numerous. Hermaphrodite flowers also 

 sometimes occur. In the north Frisian island Eom, and 

 in the Tyrol, both kinds of flowers secrete honey and are 

 visited by insects. In mid -Germany, according to 

 Schulz, the nectaries of the male flowers secrete no 

 honey, and though the female flowers still produce 

 some, yet from the close adherence of the calyx and 

 corolla it is not accessible to insects in the normal way. 



Saponaria 



While Lychnis has 5, or rarely 4, and Silene 3 styles, 

 in Saponaria there are only 2. 



S. officinalis (Soapwort) is a protandrous moth-flower. 

 The calyx forms a tube 18-21 mm. in length. The 

 pink, or white, petals are obcordate, and abruptly con- 

 tracted into a long narrow claw. The five outer stamens 

 ripen first, and open their anthers just over the flower. 

 When they have shed their pollen they shrivel up and 

 make way for the inner five stamens. When these, in 

 their turn, are exhausted, the two stigmas elongate and 

 take up the same position. The honey is in the base 

 of the long tube, and only accessible to hawkmoths and 

 some moths. The hawkmoths Sphinx ligustri, S. con- 

 volvuli, and Macroglossa stellatarum (the Humming- 

 bird hawkmoth) appear to be the most frequent visitors. 

 The flowers are very sweet at night ; in the day their 

 scent is faint. The plant is protected by a poisonous 

 ingredient in the sap. 



Alsine^ 



In the second division of the Caryophyllaceae the 

 sepals are separate, or but slightly connected at the 

 base. The petals therefore can separate, and the honey, 

 which is generally secreted at the base of the stamens. 



