DANDELION 65 



There are bristly points near the top of the inferior ovary which 

 affix it to the soil. 



The Dandelion is about 8 in. high. The plant flowers from March 

 or April till October. It is perennial and propagated by division. 



The flowerheads are conspicuous. They close up at night and 

 when it is raining. They open at 5-6 a.m. and close between 8 and 

 10 p.m. at Upsala, but at Innsbruck they open between 6 and 7 a.m. 

 and close between 2 and 3 p.m., showing that a slight difference in 

 latitude greatly affects the opening of flowers. 



In each capitulum there are 100-300 florets. It measures 30-50 

 mm. across, though the receptacle is 5-7 mm. across. The tube is 

 3-7 mm. long. The honey rises high up the tube. The style nearly 

 fills the tube. The anther cylinder, 2^-5 mm. long, projects from 

 it, and the style is 3-5 mm. above this after lengthening. Upon 

 this projecting portion are pointed hairs which sweep the pollen out 

 of the tube and accumulate it. The style branches are 1^-2 mm. 

 long, and covered with stigmatic papillae on the inner face. They 

 bend over and backwards, making one and a half spiral turns, and 

 in the absence of insect visitors, that may remove the pollen, self- 

 pollination occurs. 



The last phase is of advantage to the plant, which flowers peren- 

 nially when insects are not flying, as in early spring and late autumn, 

 or even winter. The pollen is variable in the same floret. 



The flower is visited by the Honey Bee, Bombns silvaruni, B. 

 confusus, B. barbutclhis, and other Hymenoptera, besides Diptera, 

 Lepidoptera, and Coleoptera. 



The fruits are provided with a tuft of hairs, forming the " clock " 

 or pappus, which assist in wind dispersal. 



The Dandelion grows on different soils, according to the forms 

 (of which there are several) into which one may split it up. It is 

 common on sand soil, other forms grow on clay soil, while one form 

 {palustre) is a peat plant and requires rather peaty conditions. 



The fungi Pnccinia variabilis, P. taraxaci, P. syhatica, and Pro- 

 toniyccs pachydermis attack the leaves. Several insects adopt the 

 Dandelion as a food plant, such as a beetle, i\Ieligcthcs syiuphyti; 

 several Hymenoptera, Andrcna albicans, A. filipcs, A. tibialis, A. 

 thoracica, A, nitida, A. nigroffnea, A. gwynana, and Lepidoptera 

 Buff Ermine (Arcf/'a lubricipcda\ The Shears (Hadena dentina}, 

 Cream Wave (Acida/ia remutata\ Gold Swift (Hcpialus hccfus), 

 Clouded Buff (Euthemonia rnssuld], Northern Rustic (A grot is luccr- 

 nca\ Great Brocade (Aplccta occultd). 



VOL. II. 20 



