Figuring against Weeds. 777 
Beginning with the foreign annuals the leading worst kinds 
given in the order of arrangement in Gray’s Botany, are: charlock 
or yellow mustard, shepherd’s purse, corn cockle, purslane, abutelon 
or velvet leaf, sun-flower, mayweed, Jamestown or jimson-weed, 
two species, goose-foot or lamb’s quarters; pig-weed, tumble-weed, 
chess and three kinds of fox-tail grass or “ puss-tail.” 
The three foreign biennials are the common carrot, parsnip and 
the hound’s-tongue. Two of these are closely related and have 
escaped from the vegetable garden where they are very important 
root crops. The carrot and parsnip are not as bad weeds in Iowa as 
they have become in many parts of the East where they cover the 
pastures and meadows with useless herbage. 
Of foreign perennials the leading worst sorts are Canada thistle, 
dandelion, rib-grass or narrow-leayed plantain, butter and eggs, 
toad-flax or ramstead weed, curled-dock and sorrel. 
Coming now to the native weeds of this most injurious class we 
find among the annuals the following: Daisy fleabane, great rag- 
weed, Roman rag-weed, cockle-bur or clot-bur, beggar’s ticks, horse 
nettle, beaked horse nettle, prostrate pig-weed, knot-grass and bur- 
grass. It will be seen at a glance that this is a formidable array of 
bad enemies. 
The biennials are the evening primrose, a kind of fleabane or 
horse-weed, and the viper’s bugloss or sometimes called blue devils. 
This makes a strong three-horse team. 
Of the native perennia's may be mentioned the callirrhoeä, two 
kinds of iron-weed, three sorts of thistles, namely : the ball thistle, 
common thistle and pasture thistle, the bracted bind-weed and 
quack or quick-grass. 
By turning the figures of the tables to further service, it may be 
shown that there are nearly twice as many foreign weeds of the 
worst sort as of the natives. Twenty-eight out of the fifty-one live 
for only a single year. Six only are biennials and seventeen are 
perennials, This we should not expect because other things 
remaining the same a perennial is a worse weed than an annual. 
But other things do not remain the same. The annual is usually 
characterized by great capacity for forming seed, and this advances 
many of the annuals to the first rank among plant pests. For 
example, the common purslane will mature a million seeds in a 
