440 ANGIOSPERMAE—DICOTYLEDONES 



According to Willis and Burkill ('Fls. and Insects in Gt. Britain,' I, p. 266), 

 the small inconspicuous sessile flowers are 3 mm. in diameter. The stigma matures 

 a little before the anthers, so that for a time crossing may result from the visits 

 of insects. Automatic self-pollination, however, regularly takes place, for the stamens 

 bend inwards and dust the stigma. All the flowers produce seeds. 



Visitors. — None were observed by Willis and Burkill. 



298. Cuphea P. Br. 



1037. C. purpurea Hort. ( = C. procumbens Orteg.). — Gaertner describes this 

 species as self-sterile. 



1038. C. micropetala H. B. et K. ( = C. eminens Planch, el Linden). (Kerner, 

 ' Nat. Hist. PI.,' Eng. Ed. i, II, pp. 235, 346.) — Kerner states that the protandrous 

 flowers of this species have their openings laterally directed. The anthers dehisce 

 on the side which faces upwards away from the stigma ; the pollen is therefore 

 likely to be carried away by nectar-sucking insects, and to effect cross-pollination. 

 Some days afterwards, the style, which has increased its length by 1 1 mm., brings 

 the stigma into the Una of access to the nectar, so that insect visitors dusted with 

 pollen must bring about crossing. Failing insect-visits, autogamy takes place by 

 the longest stamen curving up to the stigma, to which it applies its pollen-covered 

 surface. 



The obliquely placed ovary bars the way to the nectar secreted in the sacculation 

 at the base of the corolla-tube, leaving only two narrow passages through which 

 pollinating insects have to thrust their proboscis. Creeping insects (ants) are pre- 

 vented from entering the corolla-tube by adhesive bristles on the margin of the 

 calyx, such forms being useless, or even injurious to the flowers. 



299. Punica L. 



Odourless and nectarless pollen flowers, bright red in colour; homogamous 

 or protandrous. 



1039. P. Granatum L. (Schulz, 'Beitrage,' pp. 72-3.) — In this species both 

 calyx and corolla contribute to the conspicuousness of the flower. The former is 

 coral-red, very thick-walled, 26-30 mm. long and 20-25 mm. broad. The brilliantly 

 red, delicate, very fugacious petals are 20-30 mm. long and 10-20 mm. broad. 

 The numerous stamens, the filaments of which are orange-red in colour, are bent 

 inwards, and therefore block the entrance to the flower. The style is very short, 

 and may be either receptive during the dehiscence of the anthers or become so 

 after their pollen is shed. Autogamy by means of pollen that remains in the flower, 

 is possible in both cases. 



Visitors. — Schulz observed (South Tyrol) beetles belonging to the genera 

 Cetonia and Trichodes, dvg. the flowers, and often eff'ecting cross- as well as self- 

 pollination. 



