COMPOSITAE 639 



The mechanism of the numerous disk-florets agrees with that of related species : 

 their stylar branches do not curve back for more than a semicircle towards the end 

 of anthesis, so that automatic self-pollination cannot take place. 



1514. S. aquaticus Hill. 



Visitors. Heinsius (Holland) observed 2 Muscids (Lucilia cornicina F. 5, and 

 Scatophaga stercoraria Z. & and $>) and a Syrphid (Eristalis tenax Z.). 



In Dumfriesshire, a hover-fly and 5 Muscids were recorded (Scott-Elliot, ' Flora 

 of Dumfriesshire,' p. 98). 



464. Calendula L. 



Ray-florets ligulate, female; stylar branches almost smooth externally, with 

 a stigmatic line on each margin internally. Disk-florets tubular and male; end 

 of the style conical and covered with sweeping-hairs, but no trace of stigmatic 

 papillae. Kerner states that the stylar branches of the ray-florets curve till they 

 touch the pollen of the disk- florets. 



1515. C. arvensis L. (Hildebrand, ' U. d. Geschlechtsverhalt. b. d. Compositen,' 

 pp. 31-3, Taf. Ill, Figs. 10-17.) This species is monoecious. Hildebrand says that 

 the lower sweeping-hairs of the disk-florets are longer than the upper ones. Linnaeus 

 observed at Upsala that the heads open at 9 a. m., closing again about noon. 



Visitors. Schletterer observed 2 bees (Andrena parvula K., and Halictus 

 calceatus Scop.) at Pola. 



1516. C. officinalis L. (Hildebrand, op. cit., p. 33, Taf. Ill, Figs. 18-20.) 

 Hildebrand states that this species agrees in mechanism with the last one, but the tip 

 of the style thickens abruptly and is covered with sweeping-hairs of nearly uniform 

 length. According to Kerner, the stigmas of the female ray-florets become receptive 

 before pollen is pressed out of the anther-cylinders of the male disk-florets. He 

 noticed at Innsbruck that the heads open between 9 and 10 a.m., closing again 

 between 4 and 5 p. m. 



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

 stated. 



Knuth (Kiel Botanic Garden), Apis, a humble-bee (Bombus sylvarum Z.), 

 3 hover-flies (1. Eristalis arbustorum Z. ; 2. E. tenax Z. ; 3. Syrphus ribesii Z.), 

 and a Muscid (Calliphora erythrocephala Mg.) : all skg. (' Blutenbiol. Bijdragen '). 

 Wiistnei (Alsen), 3 bees (1. Megachile centuncularis Z. ; 2. M. circumcincta K. ; 

 3. Coelioxys acuminata Nyl.). 



2. Sub-order Cynareae Less. 



Stylar branches of the hermaphrodite florets usually combined into a pubescent 

 bifid cylinder with a ring of hairs or swelling at their base. Otherwise as 



CORYMBIFERAE. 



465. Echinops L. 



Stylar branches pubescent externally, with a ring of long sweeping-hairs at their 

 base ; papillose internally. 



