UNACEAE— LINUM 581 



land ; Brussels, Belgium ; in Russia, and the Nile region. The seeds are also used 

 extensively for making linseed oil. The chief regions where it is cultivated in 

 North America are the Dakotas, Minnesota, Nebraska and Manitoba. Russia 

 also cultivates the plant for the oil. The seed contains linolleic acid C H„0 , 

 and is rich in oil. The compressed refuse is manufactured into oil cake, whith 

 is used for cattle food. The flax oil found in the seed of the plant is about one- 

 third of its weight. Commercially, between 20 per cent and 30 per cent are ob- 

 tained. When fresh it is without color and has little taste. The commercial 

 oil is yellow and has a repulsive taste. On exposure to the air after having 

 been heated with oxide of lead, it dries up to a transparent varnish consisting 

 chiefly of linoxyn CggHg^O^^. In medicine the flax seed is used in the form 

 of a poultice, which is made of the pulverized seed. When oil cake or oil meal 

 is fed in concentrated form it produced digestive trouble to hogs, frequently 

 resulting in death. Dr. Schaffner states that it causes death to cattle, probably 

 due to the prussic acid evolved from the plant when wilting. This substance 

 has been reported. 



Friedberger and Frohner state that it causes violent colic, inflation, diarrhoea, 

 staggering, palpitation^ death with convulsions; autopsy shows gastro-enteritis 

 and signs of axphyxiation. 



Linum rigidum Pursh. Large-flowered Yellow Flax 



An herbaceous glaucus or slightly puberulent annual with rigid angled branch- 

 es from 1-2 feet high; leaves narrow, erect, usually with stipular glands; flowers 

 large ,yellow; sepals acute or awn-pointed, glandular, serrulate; petals cune- 

 ate-obovate longer than the sepals ; styles separate only at the summit ; capsule 

 S-valved and ovoid. 



Distribution. Loess soil of western Iowa to Missouri, Texas, Mexico 

 to Arizona and Manitoba. 



Poisonous nature. According to Chesnut the plant is reported as poison- 

 ous to sheep in the Pecos Valley, Texas. 



RuTACEAE. Rue Family 



Trees, shrubs, or herbs with simple, compound, alternate or opposite leaves, 

 glandular, with punctate dots without stipules ; flowers mostly in cymose clusters, 

 polygamo-dioecious hypogynous, or perigynous ; sepals 4-S ; petals 4 or 5 ; stam- 

 ens of the same number or twice as many, distinct, inserted on the receptacle ; pistils 

 2-5, distinct or one compound ; 2-5 carpels raised on an annular disk ; embryo large, 

 curved or straight ; endosperm fleshy or none. 



About 875 species, mostly in tropical regions of South Africa and Australia. 

 Few representatives in North America. Two species of prickly ash (Zanthoxy- 

 lum americanum Mill and Z. Clava-Herculis L.) and our hop-tree (Ptelea tri- 

 foliata) are common in the United States. The fruit of the hop-tree is used 

 in Russia as a substitute for hops. A bitter alkaloidal principle occurs in Xan- 

 thoxylum. The gas plant (Dictamnus albus) a viscid glandular plant with strong 

 aromatic scent is commonly cultivated. The common rue {Ruta graveolc-ns), 

 a native to Europe, is sometimes cultivated in country gardens.^TFTas a "strong 

 disagreeable odor, and is so acrid that it will even blister the hands. It con- 

 tains an acrid narcotic poison. The cork tree (Phellodendron amurense) from 

 the Amur region, is occasionally cultivated. The most important genus of the 



