EXPERIMENT STATION REPORT. 323 



Vaeiations in Wild Plants. 



A study of the question of variation in cultivated plants leads 

 naturally to a consideration of this subject as illustrated in wild 

 species. With the aid of a few plates and the acoompanying text, 

 something of the Avide variability of our common weeds and other 

 plants is herewith presented. 



THE DANDELION (tAR^VXACUM TAEAXACUM (l.)). 



Always at hand is the dandelion, and thirteen of these, plants 

 found upon the border driveway to the breeding grounds were 

 transplanted to good soil and given clean culture for a season, when 

 sani])le leaves were gathered for the photograph from which Plate 

 XIX. has been made. The leaves are arranged in a series from a 

 to m: and show great range in absolute size, in the amount of ex- 

 pansion and the manner in which the reduction of the surface is 

 effected. The leaf a is, at first glance, like h, but a close study will 

 show that one is much longer than the other — a difference that is 

 quite constant with plants gTown under the same conditions. Had 

 the plant a\ been shaded, as by placing a truck barrel, with both 

 heads removed, over it, its leaves would have become elongated and 

 the resemblance to b much more complete. 



It is further true that a close study of the dandelion shows that 

 upon the same plant there is sometimes quite a range of forms ; 

 thus, it may be, in rare instances, as gi'eat as from a to c or d, 

 which suggests that location upon the stem, age of leaf, food and 

 sun supply, &c., need to be considered when looking upon the vari- 

 ous forms as elementary species. Seeds have been saved of the 

 various plants involved in the picture, and, as yet, nothing can be 

 written as to the constancy of the forms in question. The pres- 

 ent p'urpose is to place on record some of the striking forms of 

 leaves in this most common wayside weed. 



It is possible that the smallest and most reduced leaf is from a 

 member of the Red-Seeded Dandelion (Taraxacum erythro- 

 spenmium And.), or it and some others are hybrids between the 

 two species named. This and the whole question of seed produc- 

 tion is one full of interest. CbrreS'pondence with lx)tanists in re- 



