132 ANGIOSPERMAE—DICOTYLEDONES 



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

 stated. — 



Herm. Miiller (his garden at Lippstadt), the honey-bee and two humble-bees 

 (Bombus agrorum F. 5, and B. terrester Z. J), skg. actively and persistently. Loew 

 (Berlin Botanic Garden), 4 bees, all skg. and po-cltg. — i . Apis mellifica L. 5 ; 

 2. Bombus agrorum F. ^■, 3. B. lapidarius L. 5; 4- Osmia rufa L. 5- ■ Schulz 

 observed flowers perforated by humble-bees. 



1990. C. major L. (Knuth, 'Blutenbiol. a. d. Ins. Capri'; Heim. Miiller 

 erroneously describes C. alpina under this name in his 'Alpenblumen.') — This species 

 bears homogamous humble-bee flowers. 



Visitors. — I observed (April, 1892) 2 long-tongued bees (Anthophora pilipes/'., 

 and A. femorata Oliv.) in the crater of the Solfatara. Morawitz noticed the bee 

 Osmia cerinthidis Mor. 



1991. C. aspera Roth. (Comes, ' Ult. stud.') — Comes describes this species as 

 self-fertile. 



613. Echium Tourn. 



Mostly protandrous bee-flowers ; with nectar secreted by the fleshy base of the 

 ovary, and concealed in the contracted lower part of the funnel-shaped coroUa-tube. 

 Sometimes gynodioecious, more rarely gynomonoecious. 



1992. E. wilgare L. (Sprengel, ' Entd. Geh.,' pp. 99-101 ; Harm. MuUer, 

 'Fertilisation,' pp. 418-21, 'Alpenblumen,' p. 262, 'Weit. Beob.,' Ill, p. 14; 

 Schulz, 'Beitrage,' I; Kirchner, 'Flora v. Stuttgart,' pp. 557-8; Jordan, Ber. D. 

 bot. Ges., Berlin, x, 1892, pp. 583-6; Knuth, ' Grundriss d. Blutenbiol.,' pp. 77-8 

 ' Bloemenbiol. Bijdragen'; Loew, 'Blutenbiol. Floristik,' pp. 391, 399.) — The large 

 blue flowers of this species make the plant extremely conspicuous from a distance, so 

 that it is visited by a very large number of insects, especially bees, hover-flies, 

 butterflies, and moths. In spite of their great difference in size all these visitors 

 are adapted to effect crossing, whether they probe for nectar or come for the pollen. 

 In the protandrous flowers the narrowest part of the corolla surrounds the nectar, 

 and is directed obliquely upwards, its bend corresponding with that of a bee's 

 proboscis. The broadened bases of the five filaments are fused with its basal 

 portion for a distance of 4 mm. At the place where they become free the corolla- 

 tube rapidly widens, so that even the largest humble-bees can conveniently insert 

 their head and a part of their thorax into the flower, while the smaller ones can 

 creep completely into it. The filaments run horizontally together from the place 

 where they become free, and the four lowest ones project 7 mm. beyond the lower 

 margin of the entrance to the flower, forming convenient alighting-rods for humble- 

 bees. Where the uppermost stamen, on the other hand, becomes free, it at once 

 bends down, dividing the access to the nectar-secreting base of the flower into right 

 and left portions, and then runs horizontally to the opening of the flower with the other 

 filaments. The free ends of all the stamens are turned slightly upwards, while the 

 anthers dehisce immediately the flower opens, and their pollen-covered surfaces face 

 in the same direction. It follows that no bee can settle on the flower without getting 

 its under-side dusted with pollen, for the larger humble-bees support their thorax and 

 smaller ones their abdomen on the long stamens, while the ventral surface of a still 



