64 NINTH REPORT. 



VEGETATIVE REPRODUCTION IN ERYTHRONIUM AMERICANUM. 



J. B. Dandeno. 



This plant has certain pecuUarities about its vegetative habit Avhich entitle 

 it to some special attention. It is not intended to go into the whole life his- 

 tory in minute detail, because much of it is not different from that of others 

 of its relatives. It is one of the commonest of our spring plants, and one 

 which, in the struggle for existence, has accjuired the habit of making its 

 year's food, flowering and seeding, during the months of April and May, in 

 this locality. And this does not imply that it reciuires two full months to 

 accomplish this. In one season it appears above ground on April 20th and 

 disappears entirely from above ground on May 28th. This period constitutes 

 what might be called its period of vegetation, or its life period. 



Very few seeds of this plant seem to set, and only a few of these can ordi- 

 narily be made to germinate in the laboratory, so that the plant seems to 

 be losing its power of propagation by seed. Whether this be so or not, it has 

 an excellent system of vegetative propagation. 



On examining with the aid of a spade in early spring when the plant 

 is in leaf, a large amount of material showing the underground parts, an inter- 

 esting point relative to the direction of growth of the stem is quite apparent. 

 Having first started from seed among the humus of the woods, or along fences 

 it produces a minute narrow-leaved plant which develops into a form as 

 represented in figure A. The leaf petiole is comparatively short, for the bulb 

 is formed ciuite near the surface. This bulb becomes in one season about 

 5 mm. long by 3 mm. Made, and this is the first year from the seed. This 

 bulb, during the following season, sends out from one to five underground 

 stems, each spreading out and pursuing a course not horizontal but slanting 

 downAvards. While this is going on, one leaf is sent up into the air. This leaf 

 is larger, broader and has a longer petiole than that of the previous year (Fig. B) 

 The following year the bulb sends out underground stems — three or four in 

 numl^er. These grow doAvnw^ards, also in a slanting direction, and the bulb 

 is developed on the tip of each. At the same time but one green leaf is sent 

 up into the air (Fig. C). In this year the bulbs at the ends of the stems be- 

 come particularly large, and the parent bulb dwindles away, becoming al- 

 most entirely absorbed. This is generally not the case in the bulbs of an}^ 

 other year. At the end of the fourth year the bulbs are as deep as they ever 

 become. So that the deepening process is accomplished during the second, 

 third and fourth years. During the fourth year the bulb develops to a very 

 considerable size, iDut there is only one leaf. During the fifth year the jilant 

 sends up two foliage leaves and also one flower stalk, but no underground 

 stems. Nor does it ever after this develop deepening stems, but goes on 

 from year to year by producing from one to three new bulbs just in immediate 

 connection with the old one, in a similar manner to that of the conunon 

 onion. In the following years it produces a flower about every other 3'ear, 

 of course from the same location in the soil, so that whatever creeping the 

 plant does is accomplished during the first four years from seed. The length 

 of the petiole A^aries necessarily with the depth of the bulb from which it 

 grows. 



