PROTECTION OF POLLEN 8i 



more the anthers come under the shelter of the petals : Campanula patula, Geranium 

 Robertianum, Anemone nemorosa, Stellaria graminea, Solanum tuberosum, Pole- 

 monium coeruleum, Scabiosa lucida, Bellis perennis, Doronicum, Sonchus, Tussilago, 

 Astrantia alpina and carniolica, Sisymbrium Thalianum; Epilobium montanum, 

 hirsutum, roseum, and many others. 



(d) The flowers are sheltered under foliage leaves : Limes, Impatiens Noli- 

 tangere, Daphne Laureola, Althaea rosea, and others. 



{e) The inflorescences are roofed over by a large spathe : Many Aroids. 



(/") The petals close together above the stamens : TroUius europaeus. 



(^) The opening of the floiver is lateral'. IMany Labiates, Pinguicula, Alectoro- 

 lophus, Melampyrum, Euphrasia, Viola, Aconitum, and others. 



{h) The flowers are entirely closed: All Papilionaceae, Corydalis, Linaria, 

 Antirrhinum. 



(?) The stigjuas form a protective roof over the anthers : Iris. 



{k) The ligulate florets of Composites protect the pollen : Lactuca, Hieracium, 

 Lapsana, Cichorium. 



(/) The pollen is enclosed in an anther-tube, from which it is only discharged by 

 a shortening of the filaments when these are disturbed by insect-visits: Onopordon, 

 Centaurea. 



2. The corolla-tube of funnel-shaped flowers is contracted at the 

 opening, so that no drops of water can enter: Species of Phlox, Daphne, 

 Androsace, and Aretia. 



3. The flowers or inflorescences close in unfavourable weather. 



{a) The ligulate ray florets, or the involucral bracts close over the disk-florets : 

 Carlina. 



{b) The whole flower closes in dull or rough weather: Colchicum, Crocus, 

 Erythraea ; species of Gentiana, Campanula, and Ornithogalum ; paeonies, roses, 

 Datura Stramonium, Nymphaea, Eranthis, Anemone, Eschscholtzia. 



4. The anthers that have dehisced in dry weather close up again 

 in moist weather: Plantago, Globularia, Alchemilla, Laurus nobilis, Thesium, 

 Bulbocodium, Thalictrum, Vitis, Liriodendron, Cistus, and others. 



5. The pollen-grains are covered with pits, sufficiently deep to prevent 

 the air contained in them from being driven out by water, so that it forms a layer 

 protecting the pollen-grains from being wetted : Cobaea. 



In many plants several of these protective devices are present. Most of the 

 arrangements for the protection of pollen are otherwise advantageous, especially with 

 regard to the possibility of self-fertilization, and the protection of nectar. 



A. Hansgirg (SitzBer, Bohm. Ges. Wiss., Prag, xxxiii, 1896) describes as 

 ombrophobous (rain -fearing) such flowers as are able by special movements (ombro- 

 phobous movements) to protect themselves against the injurious eff"ect of rain or 

 continued wetting ; flowers that are not able to execute such movements he terms 

 anom brophobous. 



The ombrophobous plants of temperate regions belong to the Xerophytes. 

 The ombrophobous movements cease as soon as the protection of nectaries or 



DAVIS G 



