en 



LIBRARY 

 NEW YORK 



TORREYA ZtlT 



QAI«OeN. 



May, igog 

 Vol. 9. No. 5. 



REPRODUCTION BY BUDDING IN DROSERA * 



In August, 1907, young plants were found growing from old 

 leaves of Droscra rotundifolia (Fig. i) in the propagating houses 

 of the New York Botanical Garden. At first they were thought 

 to be seedlings but further observation showed that they had no 

 cotyledons, no nepionic leaves like those of seedlings, no roots 

 with one exception (Fig. 5), while they bore glandular foliage 

 leaves like those of the adult plant except in size. Hence it was 

 evident that the young plants were produced from the budding 

 of the old tissue. In some cases the leaves upon which they 

 grew were green and apparently normal ; in others, brown and 

 decaying. 



Microtome sections through the point of connection between 

 the young plant and the parent tissue (Figs. 2 and 3) showed no 

 union between the vascular tissue of the parent plant and that of 

 the young plant. A differential stain (Haidenhain's iron haema- 

 toxylin) showed the difference between the vigorous tissue ol the 

 young plant and the disintegrating tissue of the parent plant very 

 clearly, but Delafield's haematoxylin showed no such distinction. 

 In each case, the stem of the young plant gave rise to five or 

 six leaves before the root appeared as a lateral outgrowth. The 

 root had a red apex and was diageoiropic until it had passed be- 

 yond the margin of the old leaf, when it bent downward into the 

 sphagnum in which the original plants were growing. In one 

 case only (Fig. 5) was a root observed on the under (non-glan- 

 dular) surface of the leaf. Later, leaf-petioles and one flower- 

 stalk (Fig. 6) that had accidentally been broken from a plant were 



C> found to be proliferating in a similar way. 



' This growth from an inflorescence is noteworthy because so 



* Illustrated with the aid of the Catherine McManes fund. 



^>— [No. 4, Vol. y, of TORRKYA, comprising pages 65—88, was issued April 8, 1909.] 



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