692 ANGIOSPERMAE—DICOTYLEDONES 



1644. M. Plumieri DC. ( = Sonchus Plumieri L., and Lactuca Plumieri Gren. 

 et Go</r.).— Kerner says that the heads of this species open at Innsbruck about 

 6-7 a.m., closing again about 8-9 p.m. 



50a. Sonchus Toum. 



Florets yellow. Style covered externally with sweeping-hairs directed obliquely 

 upwards : stylar branches beset with stigmatic papillae internally. 



1645. S. oleraceus L. (Kirchner, 'Flora v. Stuttgart,' p. 745; Herm. Mailer, 

 'Fertilisation,' p. 361; Knuth, 'Bl. u. Insekt. a. d. nordfr. Ins.,' pp. 98, 162.) — 

 In this species the expanded heads are about 20 mm. in diameter, and Kirchner 

 says they contain about 120 bright-yellow florets, the marginal ones being tinged 

 with reddish-grey on the outside. The corolla-tube is 10 mm. and the ligule 

 6 mm. long ; the anther-cylinder is orange-yellow, while the style and its branches 

 (scarcely i mm. long) are covered with blackish sweeping-hairs. The branches 

 ultimately diverge and bend round into a semicircle. Linnaeus says that the 

 heads open at Upsala at 5 a.m., closing again between 11 a.m. and 12 noon. 

 Kerner gives the corresponding times for Innsbruck as 6-7 a.m. and 1-2 p.m. 



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

 stated. — 



Knuth (Schleswig-Holstein), a humble-bee, 2 hover-flies, and a Lepidopterid. 

 Herm. Miiller (Westphalia), 3 hover-flies (i. Eristalis arbustorum Z. ; 2. Syrphus 

 arcuatus Fall. ; 3. S. balteatus Deg. : all skg. and po.-dvg.) and a butterfly (Pieris 

 brassicae Z., skg.). Schletterer (Pola), the small bee Halictus villosulus K. Scott- 

 Elliot (Dumfriesshire), 2 hover-flies and 3 Muscids ('Flora of Dumfriesshire,' p. 103). 



1646. S. arvensis L. (Kirchner, 'Flora v. Stuttgart,' p. 745.) — Kirchner says 

 that in this species the heads contain over 200 golden-yellow florets, and spread out 

 to a diameter of 40-50 mm. The corolla-tube is 8-12 mm. and the ligule 8-14 mm. 

 in length. The stylar branches ultimately roll back so far as to make a spiral of 

 three turns, and of course automatic self-pollination is thereby effected. 



The marginal florets close in dull weather. Linnaeus says that the heads 

 open at Upsala in clear weather about 6-7 a.m., closing again at 10 a.m. The times 

 given by Kerner are about 7-8 a.m. and 1 2-1 p.m. 



Visitors. — Knulh observed the following. — 



In Schleswig-Holstein (' Bl. u. Insekt. a. d. nordfr. Ins.,' p. 162 ; Weit. Beob. ii. 

 Bl. u. Insekt. a. d. nordfr. Ins., p. 237). — A. Diptera. Syrphidae : all skg. : i. Eri- 

 stalis arbustorum Z. ; 2. E. tenax Z. ; 3. Syrphus balteatus Z>^^. ; 4. S. pyrastri Z. ; 

 5. S. ribesii Z. B. Hymenoptera. Apidae: 6. Apis mellifica Z., skg. and 

 po-cltg. ; 7. Dasypoda plumipes Pz., po-cltg. C. Lepidoptera. Rhopalocera: 

 8. Pieris napi Z., skg. ; 9. P. rapae Z., do. In Helgoland (' Bl. u. Insekt. a. Helgo- 

 land '), the Muscid Lucilia caesar Z., common, and small Muscids. 



Alfken gives the following. — 



In Juist. — A. Diptera. (a) Muscidae: i. Cynomyia mortuorum Z. {b) Syr- 

 phidae: 2. Eristalis arbustorum Z. B. Hymenoptera. (a) Apidae: 3. Bombus 

 lapidarius Z. $ ; 4. B. muscorum F. t; 5. B. terrester Z. ; 6. Dasypoda plumipes Pz. 

 5, freq., po-cltg. {b) Sphegidae : 7. Oxybelus mucronatus F., very common ; 8. O. 

 uniglumis Z., rare. C. Lepidoptera. Pieridae : 9. Pieris brassicae Z. At Bremen, 

 4 bees — I. Bombus lapidarius Z. 5 ; 2- B. muscorum F.i; 3. B. terrester Z. 5; 

 4. Dasypoda plumipes Pz. 5 and 5. 



