6i6 



ANGIOSPERMAE—DICOTYLEDONES 



6 Hymenoptera, 5 hover-flies, 7 other Diptera, 4 Lepidoptera, and 3 beetles 

 (Bot. Jaarb. Dodonaea, Ghent, v, 1893, P- 4^3) ; (Pyrenees), 2 Hymenoptera, 4 beetles, 

 and II flies (op. cit., iii, 1891, p. 362). Smith (England), the bees CoUetes daviesanus 

 K. and C. marginatus Z. Saunders (England), 4 bees — i. Colletes picistig^a 

 Thorns. ; 2. Prosopis cornuta Sni. ; 3. P. dilatata K. ; 4. P. masoni Saund. Scott- 

 Elliot (Dumfriesshire), numerous Hymenoptera, flies, Lepidoptera, and beetles (' Flora 

 of Dumfriesshire,' p. 95). 



1454. A. Ptarmica L. (Herm. Muller, 'Fertilisation,' pp. 327-9 ; Knuth, ' Bl. 

 u. Insekt. a. d. nordfr. Ins.,' pp. 90, 158, ' Weit. Beob. u. Bl. u. Insekt. a. d. nordfr. 

 Ins.,' p. 236 ; MacLeod, Bot. Jaarb. Dodonaea, Ghent, v, 1893.) — The heads of this 

 species are larger than in A. Millefolium, but not so many of them are grouped 

 together, and the two species are about equally conspicuous. Hermann Muller says 

 that they occur in equal abundance, and flower simultaneously, in the same localities 



Fig. 200. Achillea moschaia, Jacq. (after Herm, MiilJer). A. A head in the course of anthesis : 

 a, stylar branches of ray-florets ; d, do. of outer disk-florets in second (female) stage ; c, inner disk-florets, 

 in first (male) stage. B. A single disk-floret in the first (male) stage : a, anther-cylinder ; gl, throat of 



corolla ; ov, ovary ; po^ pollen ; r, corolla-tube. C. Do. in the second (female) stage. Lettering as for 

 B\ £y, stylar branches. D. End of one of the stylar branches. /, sweeping-hairs ; w, stigmatic papillae. 

 E. Style with its branches rolled back. (A, B, C, S, x J- D, y. 80.) 



in Westphalia, where they are visited with equal frequency by the same insects, 

 especially by species of Prosopis, which are chiefly attracted by the odour of the 

 plant. In other places, e. g. Schleswig-Holstein, A. Ptarmica is much less abundant 

 than A. Millefolium, so that the insect visitors are also much less numerous. 



Hermann Muller describes the heads of A. Ptarmica as containing 80-100 disk- 

 florets scarcely 2^ mm. in length, which make up a surface 6-7 mm. in diameter. 

 This is extended to 15-18 mm. by means of 8-12 ray-florets, of which the tongues 

 are 4-6 mm. long, and about the same breadth. 



