PAPA VERA CEAE 61 



VIII. ORDER PAPAVERACEAE DC. 

 1. Sub-order Papavereae. 



Homogamous, slightly protogynous, rarely protandrous pollen flowers. In the 

 bud the inner floral whorls are protected by the strong calyx, composed of two 

 or three sepals, or cap-shaped. After discharging this function the calyx falls off 

 when the petals unfold. The large, usually vividly-coloured, petals make the flowers 

 conspicuous from a distance. Sometimes this is enhanced by the colour of the 

 stamens. 



39. Papaver Tourn. 



Pollen flowers with large brilliantly coloured petals. 



131. P. alpinum L. (Herm. Muller, Alpenblumen,' pp. 142-3; Kerner, 'Nat. 

 Hist. PL,' Eng. Ed. 1, II, p. 120; Hoffmann, referred to in Darwin, 'Cross- and 

 Self-Fertilisation,' p. 331.) The flowers sometimes smell of hawthorn, sometimes of 

 musk. In the Alps the petals are citron-yellow, with a paler sulphur-yellow or 

 greenish base ; in Carniola they are dark yellow ; in Lower Austria and Steiermark 

 they are white, usually with a yellow base; 



The flowers are homogamous. The pistil is situated in the middle of the 

 deeply concave corolla, which is 30 to 35 mm. wide. The 5-8 radiate stigmas are 

 mature when the flowers open, and at the same time the anthers of some of the 

 outermost of the numerous stamens dehisce. Insects visiting the flowers for the sake 

 of the very abundant pollen may therefore effect either cross- or self-pollination. 



The flowers remain half-elosed in dull weather, and Kerner states that they 

 are open only in the forenoon. The inner stamens converge together above the 

 stigmas, and dust them with pollen. This automatic self-pollination has, however, 

 very little result, for according to H. Hoffmann garden plants invariably proved 

 self-sterile (Darwin, 'Cross- and Self-Fertilisation,' p. 331). 



Visitors. Hermann Muller observed several flies in the Alps. 



132. P. nudicaule L. (=P. radicatum Rottb.). Warming states that self- 

 pollination is almost inevitable in the sulphur-yellow or white pollen flowers of this 

 Arctic species, and it must be effective, for ripe fruits have frequently been observed, 

 though owing to the dearth of insects in the Northern region, cross-pollination hardly 

 ever occurs. Focke states, however, that cultivated plants are self-sterile. According 

 to Ekstam, the diameter of the faintly odorous flower is 20-40 mm. in Nova Zemlia. 

 Self-pollination is possible here even in the bud. 



This species flowers in Spitzbergen, according to Andersson and Hesselman 

 (' Bidrag till Kanned. om Spetsbergens o. Beeren Eil. Karlvaxtflora,' pp. 41-2), from 

 the end of June to the end of August, regularly setting fruits. The corolla is 

 25-52 mm. on an average 58 mm. in diameter. Its colour is greenish-yellow, 

 often shading into white at the bases of the petals ; but frequently it may be pure 

 sulphur-yellow, or sometimes perfectly white. The peduncle becomes curved during 

 rain, so that the opening of the flower faces downwards, and wet is kept out. 

 The pollen-grains are not injured by moisture, and germinate in distilled water 

 after three or four hours. Ekstam (' Bliitenbiol. Beob. a. Spitzbergen,' p. 2 1 ) found 

 the flowers to be homogamous or feebly protogynous-homogamous in Spitzbergen, 



