96 ANGIOSPERMAE—DICOTYLEDONES 



visitors possible. The four long stamens surround the stigma and secure automatic 

 spontaneous self-pollination should insect-visits fail. 



Visitors. — Buddeberg — in Nassau — observed a short- tongued bee, Panurgus 

 calcaratus Scop., skg. Loew (' Beitrage,' p. 30) saw Vanessa urticae Z., skg., in 

 Silesia. MacLeod — in Flanders— noted a short-tongued bee, a hover-fly, and a 

 Muscid (Bot. Jaarb. Dodonaea, Ghent, vi, 1894, pp. 198-9). 



225. E. helveticum DC. (Herm. MuUer, ' Alpenblumen,' p. 150.)— Flowers- 

 homogamous. 



Visitors. — Miiller noticed Muscidae, 3 beetles, and 4 Lepidoptera. 



226. E. orientale R. Br. (Knuth, 'Blutenbiol. Herbstbeob.') — Warnstorf 

 (Verh. bot. Ver., Berlin, xxxviii, 1894) states that the pollen-grains are yellowish- 

 white, ellipsoidal, and tuberculated, 30-37 /^ long and 18-21 /i broad. 



Visitors. — In the Kiel Botanic Garden I observed hover-flies (Eristalis sp., 

 Platicheirus sp., Syritta pipiens L., Syrphus balteatus Deg) and Lepidoptera (Pieris 

 napi L.) ; all skg. 



227. E. aureum Breb. — This species is self-fertile (Comes, ' Stud. s. impolL 

 i. ale. piante '). 



228. E. crepidifolium Reichb. (Schulz, ' Beitrage,' II, pp. 14-15.) — Flowers 

 bright yellow. The base of each short stamen is surrounded by a quadrangular 

 or polygonal nectar-secreting ridge, and there are three glandular processes directed 

 obliquely upwards in front of the bases of each pair of long stamens, the middle one 

 of the three being immediately opposite the cleft between the two filaments. The 

 stigma is mature immediately after the flower has opened. At first it projects about 

 3 mm. beyond the long stamens. Subsequently the filaments elongate, the anthers 

 reaching the stigma, but they dehisce very late, so that at first only cross-pollination 

 is possible, and self-pollination can only take place towards the end of anthesis. 



Visitors. — Schulz observed Lepidoptera, bees and flies, as well as numerous- 

 small beetles (Meligethes) : these probably effect both self- and cross-pollination. 



65. Brassica L. 



Flowers yellow, and homogamous or slightly protogynous. They are usually 

 aggregated into large inflorescences, being therefore tolerably conspicuous. The 

 nectar is half concealed, and there are four nectaries, of which two are on the inner 

 side of the short stamens, and the others between the insertions of the long stamens 

 of each pair. 



229. B. oleracea L. (Herm. Muller, ' Fertilisation,' pp. 111-12, ' Weit. Beob.,"" 

 II, p. 204; Kirchner, 'Flora v. Stuttgart,' p. 297; Cobelli, Abh. ZoolBot. Ges., 

 Wien, xl, 1890, pp. 161-4; Knuth, ' Bl. u. Insekt. a. Helgoland,' ' Bl. u. Insekt. a. 

 d. nordfr. Ins.,' 'Weit. Beob.,' p. 231.) — Kerner states that the bright yellow flowers 

 are open from eight o'clock in the morning till nine o'clock at night. There are four 

 nectaries, of which two are on the inner side of the bases of the short stamens, and 

 the two others between the insertions of the long stamens of each pair. The drops 

 of nectar secreted by the former spread out on each side between the three adjacent 

 stamens and the ovary, while those secreted by the two others collect on the outside 



