COMPOSITAE 631 



461. Arnica Rupp. 



Ray-florets, female, ligulate ; disk-florets, hermaphrodite, tubular. Style of the 

 latter covered on their whole outer surface, including the somewhat expanded tip, 

 with stiff' sweeping-hairs directed obliquely upwards; closely beset internally with 

 stigmatic papillae. Styles of the ray-florets devoid of sweeping-hairs. 



1492. A. montana L. (Herm. MuUer, ' Alpenblumen,' p. 436; Wamstorf, 

 Verh. bot Ver., Berlin, xxxvii, 1896; Knuth, 'Bl. u. Insekt. a. d. nordfr. Ins.,' 

 PP- 93j 159-60.) — In this species the diameter of the orange-coloured heads is 

 1 cm. in the North Frisian Islands, almost a third of this being taken up by the 

 disk. Each of the 50-90 disk-florets possesses a corolla-tube 4 mm. long, expanding 

 into a bell 5 mm. deep, with teeth i mm. in length. The pollen pressed out of the 

 anther-cylinder projects from the bell during the first stage of anthesis ; during the 

 second the style with its branches, which gradually roll back in a circle. There are 

 about 20 ray-florets with a corolla-tube 5 mm. deep, and a tongue 2-2 J cm. long 

 and 5-7 broad. The style projects from the former, its branches being at first 

 apposed, but subsequently diverging and displaying the stigmatic papillae. 



Hermann Miiller made similar observations in the Alps. He also found 50-90 

 disk-florets, making up a surface about 20 mm. in diameter, and about 20 ray-florets 

 increasing the breadth of the head to 60-70 mm. Wamstorf adds that the rounded 

 yellow pollen-grains are closely covered with spinose tubercles, and measure 31 /a 

 in diameter on an average. When they are thrust out of the anther-cylinder of 

 a disk-floret by the apposed stylar branches they fall upon the teeth of the corolla, 

 which are beset at the edge with large blunt papillae that hold them fast. Soon after 

 the two long stylar branches have emerged from the anther-cylinder they diverge, 

 and roll back so that they not only reach the pollen-grains of the same floret 

 with their inner (stigmatic) surfaces, but frequently bring these into contact with 

 the pollen of the neighbouring florets. Automatic self-pollination and geitonogamy 

 are therefore both possible. 



Kerner also states that autogamy ultimately takes place by the rolling back of 

 the stylar branches. 



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

 stated. — 



Knuth (North Frisian Islands and at Tondern), 3 bees, 5 Lepidoptera, 10 flies, 

 and a beetle. Herm. Miiller (Alps), 3 beetles, 5 flies, 5 Hymenoptera, and 34 

 Lepidoptera. Loew (Switzerland), a Muscid (Spilogaster duplicata Mg.), and a 

 Syrphid (Cheilosia antiqua Mg.) ('Beitrage,' p. 58). Kriechbaumer (Alps), the 

 parasitic humble-bee Psithynis quadricolor Lep. S. Schiner (Austria), the Muscid 

 Tephritis arnicae L. Schletterer (Tyrol), the Alpine humble-bee Bombus alticola 

 Krchb., and the parasitic humble-bee Psithyrus quadricolor Lep. The former was 

 also seen (Tyrol) by von Dalla Torre. 



1493. A. alpina Olin et Landau. — This species is native to Greenland, arctic 

 America, Siberia, Spitzbergen, and Lapland. It is slenderer and more delicate than 

 A. montana. The involucral bracts are often purple-red at their tips or entirely so ; 

 the bright-yellow ray-florets are generally twice as long as the involucre, but are 

 sometimes only of the same length (Abromeit, ' Bot. Ergeb. von Drygalski's Gron- 

 landsexped.,' pp. 69-70). In Spitzbergen the species blooms from the beginning 



