318 Lake Maxinkuckee. Physical and Biological Survey 

 367. TRUE WATER-CRESS 



SISYMBRIUM NASTURTIUM-AQUATICUM L. 



Not abundant, and in quite localized patches. It either does 

 not find conditions favorable for spreading-, or has been only re- 

 cently introduced. One small patch was found at the edge of the 

 lake at Barnes's pier and another small patch at Farrar's. It was 

 pretty well established in a creek entering Culver Bay. In 1904 

 another small patch was found on the north shore west of the 

 depot. In flower on the northeast side of the lake June 5, 1901. 



In springy places by the Vandalia railroad between Plymouth 

 and Twin Lakes this plant grows with great luxuriance. 



368. HORSE-RADISH 



ARMORACIA ARMORACIA (L.) Britton 



Not abundant ; in flower in waste places May 20. Several 

 plants found on the ice ridg'e at the south end of the lake. 



The horse-radish has never been planted to any extent in this 

 district. In many parts of the state where planted and not kept 

 within bounds it becomes a great nuisance, especially in rather 

 moist clay. It does not spread far, as it fortunately produces no 

 seed, but every fragment of root grows with great tenacity, and 

 an eftort to get rid of the plant by hoeing out the roots is likely only 

 to increase their number by dividing them. 



369. WILD PEPPER-GRASS 



LEPIDIUM VIRGIMCUM L. 



One of the most common and variable of our plants, especially 

 variable in size and leafiness. In spite of its great abundance and 

 adaptability, it never appears to become a bad weed. Some plants 

 attain only the height of a few inches, others become a foot or 

 more high ; some have only a rosette of leaves at the base, while 

 others are leafy throughout, with a rosette of leaves at the top. 

 The leaves vary considerably in shape. Plants begin blooming 

 very early in spring — our earliest record is ]\Iay 13, though they 

 doubtless bloom much earlier. They continue blooming until killed 

 by freezing — indeed, in protected situations in mild winters, they 

 probably bloom all year. Although the g•ro^^i:h is usually inde- 

 terminate, in rich black ground, especially in a dry autumn, the 

 entire plant ripens, the leaves fall ofl", leaving a round clump of a 

 plant with innumerable small pods; these sometimes of a pleasing 

 purplish color. They were noted brightly in blossom as late as 

 November 24. The later flowers are reduced, having onlv 2 stam- 



