POLYGON ACE AE 



345 



hermaphrodite and purely female stocks, the former with styles and stamens of 

 varying length. Ekstam describes the plants of the Swedish highlands as being also 

 homogamous. 



In spite of not infrequent insect-visits and the facilities for automatic self- 

 pollination in the hermaphrodite flowers, fruits are but rarely set. The plant 

 propagates, in fact, almost always vegetatively by means of bulbils. Ekstam says 

 that the feebly odorous flowers in Nova Zemlia are protogynous-homogamous. 

 Most of them are modified into bulbils. According to Lindman, the flowers on the 

 Dovrefjeld are partly hermaphrodite, partly (and more often) female with vestigial 

 anthers. In Nova Zemlia hermaphrodite flowers are much more numerous than the 

 female ones. Andersson and Hesselman state that the species flowers in Spitzbergen 

 from the beginning of July to the middle of August ; ripe fruits were not observed, 

 but bulbils were thrown off from the middle of August (' Bidrag till Kanned. om 

 Spetsbergens o. Beeren Eil. Karlvaxtflora,' p. 65). Ekstam describes the flowers in 

 Spitzbergen as white to red-violet or red in colour, protogynous-homogamous. 

 2-4 mm. in diameter, and slightly fragrant (' Bliitenbiol. Beob. a. Spitzbergen '). 



1/ CS/ \ 



Fig. 352. Polygonum viviparum, Z,. (after Herm. MuIIerj. A. Hermaplirodite flower. B. Do., 

 with the part forcibly separated. C. Female flower, after removal of the anterior perianth leaves. D. 

 Female flower with still longer styles { x 7). a, inner anthers ; w, nectary ; p^ upper perianth leaves. 



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



stated. — 



Herm. Miiller (Alps), an Empid, a Syrphid, 2 bees, 10 Lepidoptera, and a beetle. 

 Schulz (Alps), flies, bees, and Lepidoptera. Lindman (Alps), medium-sized flies. 

 Loew (Switzerland), the Empid Empis tessellata (' Beitrage,' p. 60). Schneider (arctic 

 Norway), 7 humble-bees — i. Bombus lapponicus F. 5 and S; 2. B. nivalis Dahlb. 5; 

 3. B. pratorum L. $ and S ; 4. B. scrimshiranus K. 5 and t; 5. B. terrester L. 5 and 

 5 ; 6. Psithyrus quadricolor Lep. % ; 7. P. vestalis Fourcr. S (Mus. Aaish., Tromso, 

 xvii, 1895). Ekstam (Spitzbergen), none. 



2474. P. amphibium L. (Kirchner, 'Flora v. Stuttgart,' p. 216; Schulz, 

 ' Beitrage,' II ; Knuth, ' Weit. Beob. ii. Bl. u. Insekt, a. d. nordfr. Ins.') — The flowers 

 of this species belong to class C. They are pink to purple-red in colour, smell like 

 honey, and are dimorphous. Nectar is secreted at the base of the ovary by five 

 orange-yellow glands, and hidden in the bottom of the perianth, which is about 5 mm. 

 long. In the short-styled form this opens in the shape of a funnel, and so widely, 

 that an entrance of about 4 mm. broad is formed, in which the two globular stigmas 

 are situated, the five anthers projecting 1^2 mm. beyond them. In the long-styled 

 form the perianth leaves close up until a much narrower entrance is left, through 



