534 



ANGIOSPERMAE—DICOTYLEDONES 



]MacLeod (Belgium) saw a hawk-moth (Deilephila sp.). 



1223. L. tatarica L. (Herm. MuUer, 'Fertilisation,' p. 297.)— This Siberian 

 species, cultivated in our public gardens and so forth, bears flowers with concealed 

 nectar. Hermann Miiller says that the corolla-tube is 6-7 mm. long, and secretes 

 nectar in a shallow pouch at its base. The bright red flowers are homogamous ; the 

 anthers project a little beyond the stigma. Insects, while probing for nectar, touch 

 the stigma with one side of their heads and the pollen-covered anthers with the 

 other. When visits are repeated crossing is favoured, though, of course, self-pollina- 

 tion may also be effected. The latter may also take place automatically, for it is not 

 unusual to find flowers in which the stigma touches one or two of the anthers. 



Visitors. — The following were recorded by the observers, and for the localities 

 stated. — 



Herm. MuUer (H. M.) (' Weit. Beob.,' p. 235) and myself (Kn.) (' Bloemenbiol. 

 Bijdragen'). — A. Diptera. Syrphidae: i. Rhingia rostrata Z. (Kn., H. M.), very 

 common, skg. and po-dvg. B. Hymenoptera. Apidae : 2. Andrena albicans 



Fig. 176. Lonicera nigra, L. (after Herm. Muller). A. A pair of (lowers, seen from the front. 

 B. Lower part of a flower in longitudinal section (x 7). ?/, nectary. 



Mull. % (H. M.), vainly trying to suck ; 3. Apis mellifica L. 5 (Kn., H. M.), freq. skg. ; 

 4. Megachile centuncularis L. $ (H. IM.), skg. Alfken (Bremen), 3 humble-bees — 

 I. Bombus derhamellus K. } ; 2. B. sylvarum Z. 5 ; 3. B. lucorum Z. 5 and 5- Mora- 

 witz (St. Petersburg), 2 leaf-cutting bees, freq. — Megachile willughbiella K., and 

 M. circumcincta K. 



iza^. L. Xylosteum L. (Herm. Muller, 'Fertilisation,' pp. 297-8; Kerner, 

 'Nat. Hist. PI.,' Eng. Ed. i, II, p. 278.) — Hermann Muller describes the yellowish- 

 white flowers of this species as homogamous. The corolla-tube is only 3-4 mm. 

 long, so that the concealed nectar contained in a shallow pouch, and protected at the 

 base of the tube with hairs, is accessible even to short-tongued insects. The stamens 

 and style project far out of the flower, and the former diverge widely from the latter. 

 It follows that insect visitors touch the stamens and stigma with opposite sides of their 

 heads, and regularly effect cross-pollination. Failing such visitors, automatic self- 



