CAMPANULA CEAE 



15 



open about 7-8 a. m., and close again about 3-4 p. m. During closing the wheel- 

 shaped corolla is thrown into longitudinal folds, which take up some of the pollen, 

 transferring this to the open stigmas when closing next takes place. The anthers 

 dehisce as soon as the bud opens. During this first stage of anthesis insect visitors 

 use the pollen-covered style as an alighting-place, so that their ventral surfaces get 

 dusted. Should they now visit a flower in the second stage the)' will transfer this 

 pollen to the expanded stigmas on which they settle. Kerner says that before the 

 blossoms wither the stylar branches become so strongly recurved that their inner 

 papillose surfaces reach the end of the style and pollinate themselves automatically 

 with the grains that remain clinging to this. Autogamy can therefore be effected in 

 one of two ways, i. e. by the folded corolla when it shuts up, and by the reflexed 

 stylar branches. Kirchner found that nectar was but sparsely secreted by flowers in 

 the South Tyrol and the Hohenheim Botanic Garden, even when the weather was 

 sunny (Jahreshefte Ver. Natk., Stuttgart, liii, 1897, p. 196). 



Cleistogamous flowers have been observed, as e. g. by Kirchner (op. cit.) in all 

 the plants growing in the Hohenheim Botanic Garden, which had been grown from 

 seeds sent from the Paris Botanic Garden. They resemble the similar flowers of the 

 next species. 



Visitors. — Schletterer (Pola) observed 3 bees — i. Halictus quadrinotatus K.; 

 2. H. variipes vJ/cr. ; 3. H. vestitus j^/or. 



1726. S. perfoliata A. DC. — This species bears cleistogamous flowers, which 

 were known to Linnaeus, and were carefully described by H. von Mohl in 1863 {c/. 

 Vol. I, pp. 53-4). 



1727. S. hybrida A. DC. (Kirchner, op. cit., pp. 196-7.) — Kirchner ex- 

 amined plants of this species in the Hohenheim Botanic Garden, and found the 

 flower mechanism to be quite similar to that of S. Speculum, except that the flowers 

 are much smaller. The corolla projects vertically between the five long calyx-teeth, 

 and broadens into a funnel of which the base is 5^ mm. in diameter. It is lilac in 

 colour, passing into bright greenish-yellow at the base, and its lobes (2J mm. long) 

 are marked with a darker median line. When the flower opens the five blue or 

 bright-yellow anthers dehisce, and deposit their bright-yellow pollen on the style they 

 surround closely. They now shrivel up to some extent and become retracted from 

 the style, the three stigmatic branches of which quickly diverge and curve downwards. 

 The flowers close in the evening in the same way as those of S. Speculum. Kirchner 

 observed some tetramerous flowers, and also some in which the diameter of the 

 corolla was only 3 mm., but the mechanism of these was the same as that of normal 

 ones. 



513. Adenophora Fisch. 



Kirchner (Jahreshefte Ver. Natk., Stuttgart, lii, 1897, pp. 215-16) calls attention 

 to the epigynous nectar-secreting disk, the margin of which is swollen into a ring, 

 so that the base of the style is surrounded by a ' nectar-collar ' as in Compositae. 



1728. A. communis Fisch. (= A. lilifolia Ledd.). (Kirchner, op. cit.) — Kirchner 

 has investigated plants of this species cultivated in the Hohenheim Botanic Garden, 

 where the flowers are bright-blue or bluish-white in colour, smell like narcissus, and 



