62 CRUCIFER^ 



tained a notable quantity of sulphur ; water-cresses were of this description ; 

 and this chemist states that 100 grs. of water-cress seeds contained 0-129 gr. 

 of sulphur. He adds that this is a perfect enigma to him, as the growth 

 of the young water-cresses took place in a soil devoid of sulphur and 

 sulphates, and in a room which contained no sulphureous vapour. 



Since the year 1808, the water-cress has been largely cultivated by 

 market-gardeners near Iiondon, Paris, Edinburgh, and other largo cities ; 

 and Loudon mentions a pure stream which runs over chalk, near liickmans- 

 worth, in Hertfordshire, in which one cultivator grew four acres, and sent 

 thence a daily supply to the London market. When much exposed to the 

 light, the leaves acquire a purplish brown tint. 



* * Flowers yellow. 



2. Creeping Yellow Cress {N. syMstre).— Leaves pinnate ; leaflets 

 lanceolate cut, those of the uppermost leaves almost entire ; root creeping ; 

 pods long and narrow. Plant perennial. This is not a common cress either 

 in England or Scotland, but it occurs on some waste places and river sides in 

 both countries. The stem is about a foot high, branched and angular, and 

 the yellow blossoms are open from June to August. 



3. Amphibious Yellow Cress, Great Water Radish {N. amphi- 

 hium). — Leaves pinnatifid, or deeply serrated; roots stringy; petals longer 

 than the calyx. Plant perennial. This plant has yellow flowers from June 

 to August, and is much larger than the creeping species ; and very remark- 

 able for the long stringy roots, which, springing from the lower joints of the 

 stem, run down into the soft soil on the margins of rivers. 



4. Annual Yellow Cress (iV. terristre). — Leaves pinnatifid, somewhat 

 lyre-shaped, unequally toothed ; pods thick and oblong ; root fibrous. This 

 cress, which is about a foot high, bears from June to September small yellow 

 flowers, of which the petals are not longer than the calyx. It grows in 

 watery places, and is an annual. 



22. Hedge Mustard {Sisymbrium). 



1. Common Hedge-mustard {S. officindle).— Pods downy, closely 

 pressed to the stem ; leaves hairy, deeply lobed, with the points turned back- 

 ward, the terminal lobe large and roundish in the upper leaves, and oblong 

 in the lower ones. Plant annual. Everybody knows this common wayside 

 flower, or weed as most would term it, for it has little beauty to recommend 

 it. It may be seen all the summer long, grey with the dust of the road, and 

 looking very shaggy in its foliage ; while the yellow flowers, on a stem one 

 or two feet high, are almost too small to be noticed. It has the usual 

 pungent flavour of the mustard plants ; but in this case, that flavour is 

 disagreeable. This species is of old renown as a medicinal herb, and has so 

 much repute as a remedy for hoarseness and weak lungs, that the French 

 term it Herbe mix chanfeurs. Dr. Cullen recommends its use, when mixed 

 with honey and sugar, for pulmonary afl'ections. The Greeks gave the name 

 of Sisymbrium to some plant which they prized, but assuredly they did not 

 allude to this Hedge-mustard, for theirs was an aquatic, and had, apparently, 

 a pleasant odour; and garlands of myrtle, roses, and Sisymbrium were 



