FLORA OF WORCESTER COUNTY. 261 
A.yssum, Tourn. Alyssum. 
*calycinum, L. ; Occasional. 
CaMELINA, Crantz. False Flax. 
*sativa, Crantz. Occasional. 
Nasturtium, R. Br. Water-Cress. 
*officinale, R. Br. True Water-Cress. Common. 
palustre, DC. Marsh Cress. i 
we “var. hispidum, DC. Not rare. 
*Armoracia, Fries. Horseradish. Escaped. 
BaRrBAREA, R. Br. Winter Cress. 
vulgaris, R. Br. Common Winter Cress. 
Sisymprium, Tourn. Hedge Mustard. 
*officinale, Scop. Hedge Mustard. Worcester. 
Prof. Eaton. 
Brassica, Tourn. Mustard. 
*nigra, Koch. Black Mustard. Waste places. 
CapsELLA, Medic. Shepherd’s Purse. 
*Bursa-pastoris, Moench. Very common. 
TH asp, Tourn. Pennycress. 
*arvense, L. Field Pennycress. | Waste places. Rare. 
Lepipium, Tourn. Peppergrass. 
Virginicum, L. Wild Peppergrass. Common. 
*ruderale, L. Not common. 
Rapuanus, Tourn. Radish. 
*Raphanistrum, L. Wild Radish, Lunenburg. 
Mr. Kilburn. 
*sativus, L. Garden Radish. Occasionally spontaneous. 
CISTACEZ. 
HELIANTHEMUM, Tourn. Rock-rose. 
Canadense, Michx. Frost-weed. Common in dry grounds. 
