690 ANGIOSPERMAE—DICOTYLEDONES 



through the anther-cylinder, and soon afterwards the stylar branches diverge, lying about 

 i^ mm. above the anther-cylinder and 5 mm. above the entrance to the corolla-tube. 

 Towards the end of anthesis these branches roll back into a spiral of i^ turns, so 

 that automatic self-pollination necessarily takes place if any pollen remains among the 

 sweeping-hairs. Kerner says that the heads open about 8-9 a.m. at Innsbruck, 

 closing again about 3-4 p.m. 



Visitors. — Kirchner observed a small bee. 



1637. L. sativa L. (=L. Scariola L. according to the Index Ktwensts). 

 (Kirchner, ' Beitrage,' p. 73.) — Kirchner says that the flower mechanism is very 

 similar to that of L. Scariola. Each head contains 10-16 yellow florets which 

 develop simultaneously. The ligules are 11 mm. long, and are directed obliquely 

 outwards, so that the diameter of the expanded head is about 15 mm. The anther- 

 cylinder projects 4 mm. beyond the corolla-tube, which is 4^ mm. in length. About 

 2 mm. above the anther-cylinder the stylar branches diverge : they ultimately roll 

 back into a complete circle, so that automatic self-pollination necessarily results from 

 contact of the stigmatic papillae with the pollen-grains clinging to the sweeping-hairs. 



According to Linnaeus, the heads open about 7 a.m. at Upsala, closing again 

 about 10 a.m. Kerner gives the corresponding times for Innsbruck as 8-9 a.m. and 

 1-2 p.m. 



Visitors. — Kirchner observed various flies. 



1638. L. muralis Less. (=Prenanthes muralis Z.). (Kirchner, 'Beitrage,' 

 p. 73.) — Kirchner says that the heads of this species contain only 5, sometimes 

 only 4, bright yellow florets, with ligules that spread out horizontally, or sometimes 

 bend a little downwards, so that the inflorescence attains a diameter of 13-14 mm. 

 The florets of each head develop simultaneously. Even before complete expansion 

 the styles project from the anther -cylinders. They grow so far in an oblique 

 direction that their tips stand about 5 mm. above the level of the head. The stylar 

 branches at first curve outwards from each other, and subsequently roll downwards, 

 though not far enough to touch the pollen remaining among the sweeping-hairs. 



Warnstorf (Verh. bot. Ver., Berhn, xxxviii, 1896), however, observed the stylar 

 branches rolling back till they came into contact with the pollen, so that autogamy 

 necessarily took place. Geitonogamy, on the other hand, is only possible when the 

 head is closed. The pollen-grains are yellow in colour, polyhedral, with spinose 

 tubercles on their edges, from 40 ^ to 43 /x in diameter. 



At Neu-Ruppin the heads open between 6 and 7 a.m., closing again between 

 4 and 5 p.m. Kerner says that they open at Innsbruck between 7 and 8 a.m., and 

 close again about 2 or 3 p.pi. 



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

 stated. — 



Kirchner (Stuttgart), 2 flies, a small bee, and the beetle Meligethes. Herm. 

 Miiller (Fichtelgebirge), a Muscid (Echinomyia grossa L., po-dvg.), and a bee 

 (Halictus albipes F., skg.) (' Weit. Beob.,' Ill, p. 96). MacLeod (Pyrenees), a bee 

 of the genus Panurgus (Bot. Jaarb. Dodonaea, Ghent, iii, 1891, p. 367). 



1639. L. perennis L. (Herm. MUller, ' Alpenblumen,' pp. 463-4.) — In this 

 species each head contains about 16 florets, which spread out their ligules (16-18 mm. 



