THE HEREDITY OF "ROGUE" TYPES IN GARDEN PEAS 



{I'lHUM SATIVUM). 



WILBEK BROTHERTON, JR. 

 DESCRIPTION OF MATERIAL. 



I'huiliiigs of ceilaiii verieties of the garden pea, I'isum salivuui, uccu- 

 sioiially contain plants (Icseribed as "wild" or "vetch-like," whose origin was 

 long in doubt. These "rogues," as they are called, are characterized chiefly 

 by a reduction in the width of the pods and of the foliar parts (leaf blades 

 and stipules). In the case of the Gradus variety, for example, the foliage of 

 the rogues is coarser in texture than that of typical plants, darker green, and 

 smooth rather than wavy. In height the rogues, on the whole, make a taller 

 and ranker growth. The increase in height may be due^ to an increase in 

 number of the internodes as well as to an increase in their length. Associated 

 with increased height is often a difference in flowering time, so t'hat the rogues 

 mature on the average later than does the typical form. The varieties in 

 which rogues are found have large, wide pods that may or may not be slightly 

 curved along the ventral suture. Seemingly correlated with the reduction in 

 width of the foliar parts is a reduction in size of the pods and an increase 

 in their curvature, so that rogue pods are often spoken of as "sickle-shaped." 

 With a change in shape of pod comes a change from the sub-cuneiform seed 

 of the varietal type to "drum-shaped" seeds in the rogue. (The seeds of the 

 type are sliown in Plate VII a ; those of the rogue in Plate VII b). The rogue 

 seeds are on the average slightly smaller in size than type seeds. Thus, in the 

 variety "Gradus" the average weight of 17S seeds from three type plants was 

 O.oOO grams, and that of 224 seeds from three rogue plants was 0.270 grams. 

 However, it is the difference in shape which is most characteristic of the. dry 

 rogue seed. In the green state the seed of the rogue is bitter to taste, as 

 compared with the sweet flavor of the type seed. In other characters, such 

 as color and surface (whether wrinkled or smooth), the rogue .seed is like 

 the variety from which the rogue originated. 



It should also be mentioned here that the rogues show a decrease in the 

 size of the floral parts so that the petals are smaller than in the normal plant. 

 In regard to hardiness and productiveness the rogues equal and sometimes 

 surpass the type, although occasionally sterile rogues are met with. Plates 

 VIII and IX show, respectively, herbarium specimens of the uj>per part of a 

 mature type plan I and a rogue plant. 



INTERORADl Nti TvOOUES. 



On three occasions plants classified as type when developed to the 7th 

 or 8th node, were later characteristic rogues at the upper nodes. Plants of 



21st Mich. Acad. Sci. Kept.. 1919. 



