MIXT 201 



Of course the crop of the first year's growth is more free from 

 weeds than during the subsequent years and the oil is corres- 

 pondingly purer. The weed which causes most trouble in America 

 is the Erechtitcs hieracifolia, Eaf., known as "broom-weed," 

 " mares-tail," " fire-weed," &c., a composite plant yielding a volatile 

 oil which is bitter and pungent, and by its presence impairs the 

 naturally fresh, penetrating and delicious taste of the pure oil of 

 peppermint. 



Another weed which gives almost as much trouble is the 

 Erigeron canadense, Lin.* 



In England also the presence of weeds in the plantations causes 

 considerable damage to the quality of the oil. Some cultivators 

 make an extra payment to their workmen during the harvest for 

 separating out the weeds. A grower has been known to be obliged 

 to abandon his peppermint plantation by reason of the impossibility 

 of eradicating the Mentha arvensis (" corn-mint ") wdiich had 

 invaded it, and which, as it was impossible to separate out from 

 the crop, ruined the fine flavour of the peppermint.f 



Several other weeds are injurious in this respect, particularly 

 the " Ground Ivy " {Ncpeta glechoma, Syn. GlecJioma hcdcracea, 



* SoAverby, Eng. Bot., t. 2019. 



+ 31. arvensis (Lin. Spec. 806) is a native of Europe, and plentiful in 

 Britain. It is very common in shady places by the sides of ditches, in bogs, 

 and all moist soils. Its stem is beset with retrograde pili or villi, or in some 

 varieties is nearly glabrous. The leaves are petiolate, ovate or oblong, rounded 

 at the base, cuneated or narrowed, the floral ones all conforming to the cauline 

 ones, exceeding the flowers. The whorls are all globose, many -flowered, 

 remote ; bractes lanceolate-subulate, about equal in length to the tubular or 

 campanulate calyces. Corollas red or purplish. Stamens sometimes exserted, 

 but usually enclosed. In M. arvensis var. vulgaris (Benth. Lab., p. 179), the 

 calyx is campanulate and villous ; the pedicels glabrous ; the stem and leaves 

 villous. For figure, see Sole, Menth. Brit., t. 12 ; Smith in Trans. Lin. Soc, 

 v., p. 213; Sowerby, Eng. Bot., t. 2119 ; Reichenbach, Iconographia botanica, p. 

 24, t. 968, 970, 971, 972 and 973. Supposed to be identical with M. agrcstis. 

 Sole, Menth. Brit., t. 14, and Sowerby, Eng. Bot., t. 2120; also with M. 

 Austriaca, Jacquin, Florae Austriaca? icones, v., p. 14, t. 430, and AUioni, 

 Flora Pedemontana, i., p. 18, t. 75, f. 2. There are many other varieties of the 

 " Corn-field Mint," or " Wild Mint," but, as an eminent botanist has remarked, 

 the European mints (as is generally the case with plants which are very 

 common in highly civilized and long cultivated countries, especially aquatic 

 plants), vary much in appearance, and the repeated attempts by difterent 

 authors in difterent countries to reduce these inconstant and ephemeral 

 variations to so many species, have thrown so much confusion into this diflicult 

 genus that it is now almost impossible to clear up the chaos thus produced. 



