Vegetative Reproduction and Multiplication in Erythronium* 



By Frederick H. ]]lodgett 

 (With Platks 16-18) 



John Burroughs, in Riverby, speaking of the yellow ErytJiro- 

 niiuii as he found it in grass-covered meadows, calls attention to the 

 brittle white threads which often appear above the turf. These he 

 found were connected with the immature bulbs, from which they 

 penetrate the soil in various directions. 



The nature and purpose of these threads were studied in 1893 

 and 1894.1 They are smooth, scaleless offshoots or subterranean 

 runners, heavily charged with starch. The tip encloses a bud 

 which will become a bulb upon the death of the parent bulb. In 

 this species, and in E. albidum the runners arise from the base of 

 the parent bulb, differing in this respect from E. propidlaiis Gray, 

 which produces the offshoots from the side of the stem above the 



bulb.t 



The bulbs formed at the distant end of the runners repeat the 

 process indefinitely, producing annual crops of runners and runner- 

 bulbs until the conditions are met which result in flowering plants. 

 When the necessary vigor, depth and size are reached which cause 

 the development of a flower bud in addition to the leaf bud within 

 the bulb, the annual runners cease to be produced ; but when the 

 flowering bulb is removed from those conditions, runners are again 

 produced. The runners are first produced from the bulbs which 

 are formed during the growth of the seedling ; the last crop gives 

 rise to flowering bulbs four years or more after the seed has 

 ripened. After the runners cease to be produced, annual bulbs 

 are formed within the mature bulb, resembling the runners in their 

 structure save that there is no lengthening between the terminal 

 bud and the point of origin. 



* Read in abstract before the Society for Plant Morphology and Physiology, New 

 Haven, Dec. 27, 1899. 



t Bot. Gaz. ig : 61. 1894; and 20 : 172. 1895; with illustrations. 



J Am. Nat., July, 187 1. A new Species of Erythroniiini. Dr. Gray mentions also 

 the function of the offshoots in the species Dens-canis, Americamim ?in6. propullans. 



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