22 ANGIOSPERMAE DICOTYLEDON ES 



1747. P. Halleri All. The heads of this species contain 40 flowers on an 

 average. Autogamy may take place as in P. Michelii. 



Visitors. Herm. Miiller observed 5 flies, 3 bees, and 4 Lepidoptera in the Alps 

 (' Alpenblumen,' p. 413). 



1748. P. comosum L. (Kirchner, Jahreshefte Ver. Natk., liii, 1897, pp. 

 224-5.) This species belongs to the sub-genus Synotoma G. Don, characterized by 

 umbellate inflorescences and the permanent union of the tips of the corolla-lobes. 

 Kirchner investigated the flower mechanism in the South Tyrol, and describes it as 

 follows. 



The corolla remains a closed tube throughout anthesis until the flowers wither. 

 They are odourless, borne on pedicels 2 mm. long, and 8-20 of them are arranged 

 in a hemispherical head-like umbel. The number, however, may vary from 3 to 25. 

 The inferior ovary is 5 mm. long and the subulate epigynous calyx-teeth are 4 mm. in 

 length. The corolla is 16 mm. long, ventricose, and 5 mm. broad below, tapering 

 above, and ending in a cylindrical tube 8 mm. in length. The last part is produced 

 into five small teeth, and is of a dark -violet colour, while the lower portion of the 

 corolla is bright-blue. The dark-violet style projects for 16 mm. from the opening 

 of the corolla, which it almost completely fills. It divides at the end into two 

 (sometimes three) branches 5 mm. long, and it is covered with pollen for its entire 

 length. At the beginning of anthesis the stylar branches are apposed ; they then 

 curve outwards, and finally roll up into spirals of i^ turns, so as to render automatic 

 self-pollination possible. The five stamens possess bluish-white filaments 6 mm. long, 

 and dark anthers of the same length which dehisce introrsely before the expansion of 

 the corolla and deposit their pollen on the hairs covering the style. This elongates 

 and makes the pollen available to insects, and the stylar branches diverge afterwards. 

 After dehiscence the anthers maintain their erect position within the corolla. Nectar 

 is secreted in the base of the flower by a dark-violet ring surrounding the base of 

 the bluish-white style. It can only be reached from the mouth of the corolla by 

 a very long and thin proboscis, such as that of butterflies, which Kirchner feels sure 

 are the pollinating agents, though he did not succeed in observing their visits. 



Kirchner adduces the fact that two species such as P. comosum and P. canescens 

 belong to the same genus, although they diff"er so markedly in form and mechanism, 

 as a particularly striking example of the danger of concluding that two species are 

 pollinated in the same way merely because they are closely related. 



517. Jasione L. 



Flowers social and protandrous. Their mechanism agrees essentially with that 

 of Phyteuma, but approaches more nearly that of Compositae in the fact that the 

 investment of the pollen-covered style is made up of the basally united anthers and 

 not of the cohering corolla-lobes. Beyer states that the smaller insects only dust 

 the sides of their bodies with pollen. Larger ones simultaneously touch and pollinate 

 several of the smaU crowded flowers. 



1749. J. montana L. (Sprengel, 'Entd. Geh.,' pp. 11 5-1 8; Herm. Muller, 

 'Fertilisation,' pp. 369-73, ' Weit. Beob.,' Ill, p. 79; Verhoeff, 'Bl. u. Insekt. a. d. 



