ROSACE A E 219 



256. Agrimonia Toum. 

 Yellow, homogamous, pollen flowers with pseudo-nectaries. 



912. A. Eupatoria L. (Herm. MuUer, ' Fertilisation,' pp. 235-6; MacLeod, 

 Bot. Jaarb. Dodonaea, Ghent, vi, 1894, pp. 319-20; Kirchner, 'Flora v. Stuttgart,' 

 p. 457 ; Knuth, ' Bloemenbiol. Bijdragen.') — At the base of the two styles in this 

 species there is a fleshy ring, that looks like a nectary, though no secretion has been 

 observed. The 5-7 stamens on the margin of this disk attain the same level as the 

 stigmas, and their anthers dehisce laterally. The anthers incline inwards, and there- 

 fore come into contact with the stigmas. The individual flowers bloom for a single 

 day only, and open very early in the morning. The stamens, which are at first 

 divergent, bend inwards in the course of the day, until they touch one another and 

 the stigmas. Comparatively few insects visit the flowers, but these may bring about 

 either cross- or self-pollination. From the above description it is clear that the 

 latter occurs automatically, and it is obviously effective. 



Visitors. — Herm. Miiller (H. M.) and myself (Kn.) observed the following. — 

 A. Diptera. (a) Muscidae: i. Anthomyia sp., po-dvg. (H. M.). (b) Syrphidae: 



2. Ascia podagrica F., po-dvg. (H. M.); 3. Eristalis nemorum L., do. (Kn.); 4. E. 



tenax Z., do. (H. M.); 5. Melanostoma mellina Z., do. (H. M.); 6. Melithreptus 



dispar Loew, do. (H. M.); 7. M. pictus Mg., do. (H. M.); 8. M. scriptus Z., do. 



(H. M.); 9. M. taeniatus Mg., do. (H. M.); 10. Rhingia rostrata Z., do. (H. M.); 



II. Syritta pipiens Z., do. (H. M.); 12. Syrphus ribesii Z., do. (Kn.). B. Hymeno- 



ptera. Apidae: 13. Apis mellifica Z. 5, po-cltg. (Kn.); 14. Bombus terrester Z. 



5 and 5, do. (Kn.); 15. Halictus, small sp. ?, do. (H. M.). 



Schletterer records Bombus pascuorum Scop, for the Tyrol. 



913. A. odorata Mill. — 



Visitors. — Alfken noticed bees (Apis and Prosopis sp.) at Bremen. 



257. Ulmaria Hill. 



White, hermaphrodite, homogamous pollen flowers, devoid of nectar. 



914. U. pentapetala Gilib. ( = Filipendula Ulmaria Maxim., and Spiraea 

 Ulmaria Z.). (Herm. Miiller, 'Fertilisation,' pp. 222-3, 'Weit. Beob.,' II, p. 243; 

 Lindman, ' Bidrag till Kanned. om Skandin. Fjellvaxt. Blomn. o. Befrukt.' ; Schulz, 

 'Beitrage,' II, p. 186; Knuth, ' Welt. Beob. ii. Bl. u. Insekt. a. d. nordfr. Ins.,' 

 p. 234, ' Bloemenbiol. Bijdragen.) — 



The flowers of this species are yellowish-white in colour, and associated in dense 

 crowded inflorescences. Their conspicuous appearance, and the strong odour of 

 almonds they exhale, attract numerous insect visitors, to which a large quantit}- 

 of pollen is afforded. According to Hermann Muller's account the stamens at first 

 incline together in the middle of the flower, so as completely to cover the stigmas. 

 They then gradually erect themselves in centripetal order, and bend somewhat out- 

 wards. Meanwhile the anthers dehisce, and get covered with pollen all round. 

 When the innermost stamens have become erect, the centre of the flower occupied 

 by the stigmas is the most convenient alighting-place for insects. These can 

 therefore easily effect crossing, though they are just as likely to bring about self- 

 pollination. Faihng insect visitors automatic self-pollination takes place. Owing to 



