CARYOPHYLLEAE 183 



sunshine, forming an almost plate-like disk, measuring about 8 mm. in diameter. 

 The five white spathulate petals are about the same length as the bright green sepals. 

 Of the ten stamens, the five opposite the sepals mature first. They are then nearly 

 erect, and project from the fiovifer about i mm. The five other stamens — which have 

 meanwhile rested on the petals — next mature, elongating till they are as long as the 

 outer ones. It is only at this stage that the stigmas unfold. At the base of 

 the ovary there is a large yellow nectary between each pair of stamens, which 

 secretes so abundantly that the intervals between the pairs of stamens are completely 

 filled with nectar. 



In spite of its abundant nectar the flower is seldom visited by insects. I saw 

 no visitors in the island of Rom, though I watched for a long time during fine 

 weather. From dehisced anthers, however, pollen 

 frequently falls into the flower, and this may 

 be carried by the wind to the stigmas of the 

 same plant, or of neighbouring ones. Small 

 grains of sand are constantly to be found in 

 the flowers, into which they have been drifted 

 by the wind, and as these may be blown along 

 from blossom to blossom they possibly serve as 

 occasional agents of pollination. During dull 

 weather the flowers close, so that automatic fig. 53. Honckenya pepioidcs, EUrh. 

 self-polUnation is then possible. !:;TeTrh.if:nlffi?s™:;tafe',r; 



In Greenland, Iceland, north Norway, Spitz- from above, k, sepal ; p, petal ; «, stamen of 



_ ,. J- i. Tir • '^^ outer whorl with dehisced anther: o', 



bergen, and Nova Zemha — accordmg to Warmmg stamen of the inner whorl, with anther stiii 

 —hermaphrodite flowers are very rare, and closed; s, immature stigma; ?, sand-grain. 



dioecism, polyoecism, or monoecism almost 



always obtains. Warming observed fruits to be set in Greenland. 



This species flowers in Spitzbergen from the beginning of July to August 

 (Andersson and Hesselman, 'Bidrag till Kanned. om Spetsbergens o. Beeren Eil. 

 Karlvaxtflora,' p. 64). Ekstam observed ripe fruit there on August 24, 1897. 

 Both female and hermaphrodite flowers were found. The latter are protandrous 

 and odourless, with a diameter of 9-1 1 mm., and with functional nectaries at the 

 bases of the filaments. 



Visitors.— On the dunes of Helgoland, I observed (June 8, 1895) 2 Muscidae— 

 Lucilia caesar Z., and Fucellia fucorum Fall— \io\h skg. Ekstam (' Blutenbiol. 

 Beob. a. Spitzbergen,' p. 28) observed no visitors in Spitzbergen. 



Verhoeff' observed the following 2 Muscidae in Norderney :— i. Lucilia caesar 

 L., 9 and S, skg. 2. Scatophaga stercoraria Z. 



In Dumfriesshire 2 Muscidae have been recorded, freq. (Scott-Elliot, 'Flora 

 of Dumfriesshire,' p. 26). 



132. Moehringia L. 



Flowers white, homogamous, protandrous or protogynous, with half-concealed 



nectar. 



459. M. trinervia Clairv. (=Arenaria trinervia Z.). (Herm. MuUer, 

 'Fertilisation,' 136-7, ' Weit. Beob.,' II, p. 225; Wamstorf, Verh. bot. Ver., Berlin, 



