Manchester Memoirs, Vol. liv. (1909), No. 3. 



III. A Note on the Staminal Mechanism of Passiflora 



Caertilea, L. 



By T. G. B. Osborn, B.Sc, 



Lecturer in Economic Botany, The Victoria University, Manchester. 

 Received and read November 2nd, igog. 



The greenhouses at present occupied by the Depart- 

 ment of Economic Botany, in the Victoria University, 

 contain several Passion flower vines (^Passiflora caerulea, 

 var. Constance Elliott), so that I have been afforded an 

 excellent opportunity of observing the flowers at all 

 stages of their anthesis. 



As my own observations do not agree in all respects 

 with those quoted by Knuth in " The Handbook of 

 Flower Pollination," it has seemed well to bring them 

 together in this note. 



Three references to observations on Passiflora are 

 given by Knuth; Sprengel (1793), Herm. Miiller (1883), 

 and Warnstorf (1896). 



According to Knuth the latter says : " When the bud 

 opens the anthers have already dehisced, and are directed 

 outwards, in a line with the thick stiff filaments. As the 

 flower fully expands each anther rotates through an angle 

 of 180° in the vertical plane of its filament, so as to bring 

 its pollen-covered lobes towards the interior of the flower. 

 There is next a second rotation of 90° into a horizontal 

 plane cutting the first at right angles, so that the anther 

 finally comes to be at right angles to the tip of its fila- 

 ment with the dehisced surface facing downwards." 



December J th, igog. 



