COMPOSITAE 



671 



Miiller says that they contain only 8-17 florets with corolla-tubes 1^-2^ mm. and 

 ligules 4-6 mm. long, the whole diameter being only 8-10 mm. The style projects 

 i-2 mm. from the anther-cylinder, which in turn exceeds the corolla-tube by 

 2-3 mm. The stylar branches are only mm. long. During the second stage 

 of anthesis, they diverge widely in such a way that automatic self-pollination is 

 regularly effected, if insect visitors have not previously removed the pollen. Kerner 

 states that the heads open between 6 and 7 a. m. in favourable weather, closing again 

 as early as 10 or n o'clock in the forenoon; in unfavourable weather they remain 

 completely closed. According to Warnstorf, they open between 6 and 7 a.m. at 

 Neu-Ruppin, and close again between 3 and 4 p.m. The pollen-grains are yellow 

 in colour, and polyhedral ; they bear spinose tubercles on their edges, and average 

 31 fi in diameter. 



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

 stated. 



Knuth (North Frisian Islands) 3 hover-flies. Herm. Miiller (Westphalia), 

 3 po-dvg. hover-flies (1 Eristalis arbustorum Z. ; 2. E. nemorum Z. ; 3. E. sepulcralis 

 Z.); Buddeberg (Nassau), a hover-fly (Ascia podagrica F., po.-dvg.), and 3 bees 

 (1. Halictus leucozonicus Schr., po-cltg. ; 2. H. morio F. $, skg. ; 3. H. smeathmanellus 

 K. $>, do.). MacLeod (Flanders), a hover-fly, 3 Muscids, and a Lepidopterid (Bot. 

 Jaarb. Dodonaea, Ghent, v, 1893, p. 428); (Pyrenees), a Muscid (op. cit., iii, 1891, 

 p. 364). Scott-Elliott (Dumfriesshire), a short-tongued bee, a hover-fly, and 3 Muscids 

 ('Flora of Dumfriesshire,' p. 108). 



483. Aposeris Neck. 



1605. A. foetida Less. (=Hyposeris foetida Z., and Lampsana foetida F. W. 

 Schmidt). (Briquet, 'Eludes de biol. flor. dans les Alpes Occident.') Briquet says 

 that in this species the head contains 10-25 yellow florets, and has a diameter 

 of 25-30 mm. Each floret possesses a Iigule 13-15 mm. and a corolla- tube 

 2-2^ mm. in length. The anther-cylinder is about 4 mm. long, and the style 

 projects as far beyond it, ultimately rolling back its branches so far that they 

 can be self-pollinated. 



Visitors. Few in number. Kirchner says they are beetles, Diptera, and 

 even humble-bees, which effect both cross- and self-pollination. 



484. Arnoseris Gaertn. 



Heads small and yellow. Style (below the cleft) covered with short sweeping- 

 hairs that stand out horizontally; inner surfaces 

 of the stylar branches beset with stigmatic papillae. 



1606. A. minima Dum. (=A. pusilla 

 Gaertn., and Hyoseris minima Z.). (Knuth, 'Bl. 

 u. Insekt. a. d. nordfr. Ins.,' pp. 96, 161; 'Weit. 

 Beob. ii. Bl. u. Insekt. a. d. nordfr. Ins.,' p. 229.) 

 The heads of this species examined by me in the 

 island of Fohr were 8 mm. in diameter. They 

 consisted of 20-5 florets, each 6 mm. in length; 

 the Iigule was 3 mm. long and i-| mm. broad. 

 In the second stage of anthesis the stylar branches diverge in a crescentic manner. 



Fig. ao8. Arnoseris minima, Dum- 

 (from nature, enlarged), (i) Stylar branches 

 () closed ; g, stylar brush. (2) Do., di- 

 verging ; />, pollen-grains on the brush. 



