SCROPHULARINEAE 163 



former does not serve as an alighting-platform, for after the flower opens it 

 becomes reflexed. The stiff" filaments, which project straight out of the flower, 

 perform this function, especially the two somewhat longer lower ones, placed 

 below its centre. The filaments are clothed with clavate hairs. The style runs 

 out between the two lower stamens at the same or a lower level, and since it 

 projects beyond them the stigma must be first touched by insect visitors, and 

 cross-pollination ensured. Automatic self-pollination becomes possible when the 

 flowers fade, for then the stamens bend upwards and backwards and the style 

 more strongly downwards, while the corolla curves somewhat to the front. {Cf. 

 also the remarks of Maury under V. thapsiforme.) 



Visitors. — Loew saw the Tenthredinid AUantus scrophulariae L. in the Berlin 

 Botanic Garden, and Herm. Muller gives the following list for Thuringia. — 



A. Coleoptera. (a) CurcuUonidae : i. Cionus hortulanus il/arj^., sometimes 

 inside the flowers; 2. Gymnetron tetrum F., do. {b) Telephoridae : 3. Danacea 

 pallipes F., freq. in the flowers, po-dvg. (?). B. Diptera. Muscidae : 4. Anthomyia 

 sp., po-dvg. C. Hemiptera. 5. Anthocoris sp. D. Hymenoptera. Apidae : 

 6. Halictus leucopus -S'. 5; 7. H. minutissimus K. j, po-cltg. ; 8. H. nitidus 

 Schenck 5, do. 



2049. V. nigrum L. (Sprengel, ' Entd. Geh.,' p. 122; Herm. Muller, ' Fer- 

 tihsation,' pp. 429-30, ' Weit. Beob.,' Ill, p. 26; Kirchner, 'Flora v. Stuttgart,' 

 pp. 576-7; Warnstorf, Verb. bot. Ver., Berlin, xxxvii, and xxxviii, 1896.) — The 

 yellow flowers of this species are aggregated into elongated inflorescences, and 

 their conspicuousness is still further enhanced by violet hairs on the filaments, 

 and the orange-red anthers. The centre of the base of the corolla is marked 

 with five chestnut-brown patches, alternating with the bases of the filaments, and 

 Sprengel regarded these as nectar-guides, although he was unable to find any 

 nectar. The observations of Hermann Muller confirm this view, for he found 

 a small moth (Ephestia clutella Hbn.) sucking at the place thus indicated. In 

 many flowers he also noticed minute droplets of nectar on the smooth shining 

 inner side of the short corolla-tube. 



Except that they are of smaller size, the homogamous, almost vertical flowers 

 agree essentially as to their mechanism with those of V. thapsiforme. The five 

 stamens project almost horizontally, for they diverge but little, and are only 

 slightly bent upwards. They are ^ of unequal length: the uppermost one being 

 the shortest, and the two lower ones the longest. The anthers dehisce extrorsely 

 and cover themselves all over with pollen. The style is a little shorter than 

 the lowest stamens, but is usually somewhat bent downwards, so that an insect 

 alighting on the lowest petal and turning towards the anthers will generally touch 

 the stigma first. In spite of homogamy, cross-pollination by insect-visits is thus 

 favoured. But should these fail, automatic self-pollination can easily take place, 

 for the stigma is often situated in the line of fall of the pollen. Gartner and 

 Darwin, however, state that it is entirely without effect. 



Warnstorf describes the pollen-grains as orange-red in colour, biscuit-shaped, 

 longitudinally furrowed, closely beset with delicate papillae, 19-20 fj. broad and 

 37-5 yn long. 



