48 ANGIOSPERMAEDICOTYLEDONES 



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

 stated. 



Herm. MuUer (Alps), almost the same insects as for R. ferrugineum. Frey- 

 Gessner (Switzerland), 5 bees i. Bombus alpinus L.^; 2. B. mastrucatus Gerst.; 

 3. B. mendax Gerst. ; 4. B. -montanus Lep. ; 5. Osmia nigriventris Zett. ( = O. 

 criticalis Gerst). Schletterer (Tyrol), the humble-bee Bombus pratorum L. 



1775. R. lapponicum Wahlenb. (Warming, Bot. Tids., Kjobenhavn, xv, 1885, 

 pp. 35-9.) Warming says that in the homogamous Hymenopterid flowers of this 

 species the stamens diverge so much laterally that the anthers are scarcely likely 

 to touch the stigma, so that self-pollination is rendered very difficult, and crossing 

 is usually necessary. He noticed many ripe fruits. 



The flowers of the specimens collected by Vanhoffen (Abromeit, ' Bot. Ergeb. 

 von Drygalski's Gronlandsexped.,' pp. 49-51) in Greenland were situated in groups 

 of 2-4 at the ends of the branches, and surrounded in the bud by glandular scale- 

 leaves covered with a felt of woolly hairs. When the flowers open their stalks 

 are very short (5 mm.) and beset with numerous yellow glands, but subsequently 

 elongate to 10-14 "^"i- The calyx is purple-red in colour, also glandular, and 

 the edges of its teeth fringed with long hairs. The total length of the corolla is 

 8-8-5 mm., of which about half is taken up by the tube ; it is dark purple-red 

 or sometimes bright pink in colour, and its throat is lined with small hairs. 

 There are five to nine stamens, equal in length to the pistil, and usually widely 

 separate from one another. The bases of the filaments are broadened and covered 

 with small hairs, and the brown-red anthers dehisce by means of two rounded 

 apertures. The style is 8-11 mm. long, and the dark purple-red stigma is extremely 

 glutinous. Nectar is secreted by a hypogynous ring. 



1776. R. praecox. This species is native to the Himalayas. 



Visitors. Knuth (Kiel Botanic Garden) saw 2 bees, skg. (Apis mellifica Z. 5, 

 and Bombus terrester L. 5). 



1777. R. Chamaecistus L. (=Rodothamnus Chamaecistus Rekhb.). The 

 rose-red corolla of this species is not funnel-shaped as in the preceding ones, but 

 wheel-shaped. Kerner states that the protogynous flowers are inevitably cross- 

 pollinated in the first stage of anthesis. The filaments can be twisted round, and 

 are used as alighting-rods by insects, which transfer pollen to the stigmas of 

 blossoms in the first stage, while in those in the second-stage they rub off" the 

 pollen-tetrads which are united together by threads of viscin. Ultimately the flower 

 sinks down till the stigma is brought into the line of fall of the pollen, rendering 

 automatic self-pollination possible. 



1778. R. Vanhoeffeni Abrom. Vanhoffen found only a single plant of this 

 species in Greenland, which was growing between thick clumps of Vaccinium 

 uliginosum and Betula nana. In some respects it appears to be closely related 

 to R. lapponicum, in others to Ledum palustre L., var. jB decumhens Ait., so that 

 it is possibly a hybrid between them. It is distinguished from R. lapponicum by 

 more numerous flowers in the inflorescence, longer pedicels, a smaller corolla less 

 deeply cleft and with a tube only 1-2-5 "^"i- lo"gj as well as by a series of vegetative 



