COMPOSITAE 659 



exposed. The stylar branches are short, covered externally with sweeping-hairs 

 (which are somewhat longer beneath the cleft) and beset with stigmatic papillae 

 internally. At a late stage they diverge at an acute angle. The inner straw- 

 coloured linear involucral bracts here play the part of the ray-florets of other 

 Compositae, and periodically bring about opening and closing, so that the stigmas 

 of the older florets are brought into contact with the pollen of neighbouring 

 younger ones. Geitonogamy is thus provided for, should insect-visits fail. The 

 pollen-grains are roundish, with low spinose tubercles, and are about 50 ft in 

 diameter. 



Kemer says that the heads open about 7-8 a.m., closing again 12 hours 

 later. 



Visitors.— Herm. Mailer (H. M.) ('Fertilisation,' p. 338, 'Weit. Beob.,' Ill, 

 p. 7 9) and Buddeberg (Budd.) give the following list for Thuringia and Nassau. — 



Hymenoptera. All skg. {a) Apidae: i. Bombus lapidarius Z. S (H. M.) ; 



2. B. terrester L. $ (H. M.) ; 3. B. tristis Seidl. S (H. M., Schwiebus); 4. Coelioxys 

 acuminata Nyl. 5 (H. M.) ; 5. C. quadridentata L. 5 (H. M.) ; 6. Halictus cylindricus 

 F. S, very common (H. M.); 7. H. quadricinctus F. $ (H. M., Budd.), freq. ; 

 8. Megachile circumcincta K. $ (H. M.); 9. M. lagopoda Z. S, once (H. M.). 

 (i) Sphegidae: 10. Ceropales maculatus F. 5 (H. M.). 



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



Knuth, 3 sucking humble-bees (i. Bombus derhamellus K. ; 2. B. lapidariusZ. ; 



3. B. terrester Z.), a po-dvg. hover-fly (Syrphus balteatus Deg. J), and 2 po-dvg. 

 Muscids (Olivieria lateralis F., and Anthomyia sp. 5). Schletterer (Tyrol), the 

 humble-bee Bombus derhamellus K. MacLeod (Pyrenees), 3 humble-bees and 

 a Lepidopterid (Bot. Jaarb. Dodonaea, Ghent, iii, 1891, p. 358). 



473. Saussurea DC. 



Florets hermaphrodite. Outer surface of the stylar branches completely covered 

 with long pointed sweeping-hairs, which are longest below : inner surface beset with 

 stigmatic papillae. These branches diverge and roll back. 



1555. S. alpina DC. (Herm. Miiller, ' Alpenblumen,' pp. 413-14.) — In this 

 species each head is made up of i i-i 7 florets, with a white corolla-tube 7-8 mm. 

 and a violet bell 2 mm. in length. From 5-9 such heads are closely aggregated. 

 The florets are protandrous, and smell like violets or vanilla. 



Visitors. — Hermann Miiller thinks these are probably po-dvg. flies, together 

 with po-cltg. and nect-skg. bees; but he only saw a single hover-fly. Lindman 

 observed flies, a saw-fly, and a humble-bee on the Dovreijeld. 



1556. S. albescens Hook, et Thoms. — 



Visitors. — Loew observed 3 bees (i. Apis mellifica Z. g, skg.; 2. Bombus 

 hortorum Z. S, do. ; 3. Halictus nitidiusculus K. S, do.) and an undetermined 

 Chalcidid in the Berlin Botanic Garden. 



474. Jurinea Cass. 



1557. J. mollis Reichb. (v. Wettstein, ' Compos, d. ost-ungar. Flora.') — In this 

 species the stomata of the young unopened heads secrete nectar which entices ants — 

 usually Camponotus sylvaticus Oliv., var. aethiops Laiz., more rarely Aphenogaster 



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