Naturalisation in Extra-Tropical Countries. 83 



Brassica nigra, Koch. (Sinapis nigra, Linne. ) 



The " Black Mustard." Europe, Northern Africa, Middle Asia 

 An annual. Succeeds also yet in sub-tropic latitudes. The seeds 

 crushed and passed through a sieve constitute mustard of commerce 

 For medicinal purposes the seeds of this species are preferable for 

 sinapism and especially sinapisms. Through aqueous distillation a 

 volatile oil of extreme pungency is obtained from mustard-seeds 

 valuable against rheumatism. In rich soil this plant is very prolific 

 and in forest-valleys it is likely to remain free from the attacks of 

 aphides. Chemical constituents : a peculiar fixed oil, crystalline 

 sinapiu, the fatty sinapisin, myronic acid and myrosin. All mustards 

 can be regarded as honey-plants. Brassica-seeds of various kinds 

 retain their vitality for several years. 



Brassica oleracea, Linne.* 



An annual or biennial coast-plant, indigenous to various parts of 

 Europe. Mentioned here also with a view of showing, that it might 

 be naturalised on any rocky and sandy sea-shores. One of the best 

 plants for newly reclaimed wet sour lands. From the wild plant of 

 the coast have originated various kinds of cabbages, broccoli, cauli- 

 flower, Brussels-sprouts, kale, kohl-rabi, and others, the last mentioned 

 being a variety with a very turgid stem. Plants of Broccoli have 

 been known to attain 9 feet in circumference [Dr. Masters]. A 

 variety of cabbage exists in culture, man's height, and lasting through 

 several years. Some regard the fattening qualities of cabbage as 

 superior to those of turnips, particularly for stable-food during the 

 autumnal season. The gluten of cabbages on one acre has been 

 estimated at 1,500 Ibs. against 1,000 Ibs. of gluten obtainable from 

 turnips. Other races of this species are collectively represented by 

 Brassica Rapa, L. (B. campestris, L.), the wild Navew, yielding most 

 of the varieties of turnips, some handed down to us from ancient 

 times with other cultivated forms. Again, other varieties are com- 

 prehended within Brassica Napus, L., such as the Swedish and 

 Teltower turnips, while the Raps-seed, so important for its oil (Colza, 

 from the Dutch word Koolzaat), is also derived from a form of B. 

 Napus. The Raps-plant should be, reared extensively for agrarian 

 produce, giving a rapid return, wherever it remains free from aphides. 

 Ordinary Raps is a good admixture to summer-fodder. Valuable in 

 rotation of crops. Raps sown on sandy land in Victoria sustained 

 twenty sheep on an acre during autumn and early winter, and yet the 

 land was available for other crops in the next summer. Sheep, when 

 browsing on this plant are said to be kept free from wire-worms. 

 The destruction of the Rumex- Sorrel can be aided by sowing 

 broad-cast turnips between this obstinate weed and feeding off the 

 united young growth repeatedly by sheep, the Sorrel getting suffocated 

 and tramped out [Boyce]. Important where bees are kept. The 

 hardier turnips can be produced on the highest Alps, as they are grown 

 even within the Arctic Circle, and according to Sir J. Hooker at a 

 height of 15,000 feet in the Himalayan mountains; they succeed also 



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