On the Modification of the Stamens in a Species 



of Begonia 1 ). 



Aus einem Briefe an Ch. Darwin. 



Mit 5 Textfiguren. 



Itajahy, S. Catharina, Brazil. 

 March 14, 1869. 



My dear Sir, 



In your book on 'Variation under Domestication' you mention a remarkable 

 plant of Begonia frigida producing hermaphrodite flowers with inferior perianth. 

 I have lately found an analogous wild plant of another Begonia, which is here 

 a common weed. In this plant all the male flowers show a strong tendency to 

 become hermaphrodite - - one, two, or three of the central stamens being trans- 

 formed more or less completely into pistils. No two of these male flowers appear 

 to be exactly alike; and almost every day affords a new and surprising modification. 

 Here are some cases: 



- c 



Fig. i. 



Fig. 2. 



Fig. 3- 



Fig. 4. 



Fig. 5- 



Fig. i. A single stamen modified; connectivum much dilated; on either margin a short anther with 

 good pollen; at the end, well-developed stigmatic papillse. 



Fig. 2. A single stamen modified; a well-developed stigma; neither anthers nor ovules. 



Fig. 3. Three modified stamens, united at the base, a, well-developed stigma ; no pollen; numerous 

 ovules, differing in nothing from those of the normal 9 flowers, b, club-shaped, without pollen, ovules, 

 and stigmatig papillae, c, pollen on both margins of the connectivum ; ovules on the convex margin ; apex 

 of the connectivum smooth, without stigmatic papillae, but one of the ovules transformed into a stigma. 



Fig. 4. Three stamens united, a, not modified; b, connectivum much dilated, pollen on either 

 margin, neither ovules nor stigmatic papillse ; c, well-developed stigmatic papillae, pollen (a small quantity) 

 on one margin alone of the much dilated connectivum, a few ovules. 



Fig. 5. Three stamens, modified and united: a and b without pollen, with large stigmas and 

 numerous ovules; c nearly normal, only the tip of the connectivum being somewhat enlarged and provided 

 with small stigmatic papillae. 



I) Journ. Linn. Soc. (Bot.) 1871. XI. p. 472 474. 



