GENTIANACE^E. 457 



Brucia, to which they owe their poisonous properties. These alkaloids 

 occur in combination with Igasuric or Strychnic acid. Nux-Vomica 

 and Strychnia, in poisonous doses, cause death by producing tetanic 

 spasms in the muscles of respiration. The bark of the Nux-Vomica 

 tree is the false Angustura bark, and the wood is often called Snake- 

 wood. Strychnia exists in other species of Strychnos, as S. Ignatia 

 (Ignatia amara), St. Ignatius's Bean, S. colubrina and S. ligustrina, 

 Snake-wood, S. Tieute, the source of a Java poison called Upas 

 Tieute. It is also said to exist in the Woorali or Ourari poison of Guiana, 

 which some consider to be the produce of S. toxicaria or guianensis. 

 The eifects of this last-mentioned poison, however, do not seem to 

 agree with those of Strychnia. Strychnia stimulates the spinal cord 

 without affecting the function of the brain. It causes convulsive 

 twitches of the muscles of the arms and legs, and hence it has been 

 recommended in cases of chronic palsy, unconnected with any signs 

 of local irritation or determination of blood to the head. Its adminis- 

 tration requires great caution, as f of a grain have been known to 

 produce alarming lock-jaw, and of a grain has killed a dog. Some 

 species of Strychnos seem not to possess a poisonous principle in large 

 quantity, for they are used as tonics and febrifuges. Among them 

 may be noticed Strychnos poiatorum and pseudoquina. The former is 

 called Clearing-nut, and is used in India for purifying water. The 

 root of Spigelia marilandica, Carolina Pink-root (fig. 287), is used as 

 an anthelmintic, more particularly in the United States. S. Anthelmia, 

 Guiana Pink-root, is employed in Demerara for a similar purpose. 

 These plants also possess narcotic qualities. 



948. Order 127. Gentianaccae, the Gentian Family. (Monopet. 

 Hypog.) (See fig. 248.) Calyx gamosepalous, usually in 5 divisions, 

 sometimes 4-6-8 or 10 divisions, persistent. Corolla gamopetalous, 

 hypogynous, usually regular and marcescent ; limb sometimes fringed, 

 divided into as many lobes as the calyx ; aestivation plaited or imbri- 

 cate-twisted. Stamens inserted upon the corolla, alternate with its 

 segments, and equal to them in number, some of them occasionally 

 abortive. Ovary composed of 2 carpels, unilocular or partially bilo- 

 cular (fig. 389) ; ovules 00, anatropal ; style 1, continuous ; stigmas 

 1 or 2. Fruit capsular or baccate, 1 -celled (fig. 389), usually bival- 

 vular, with septicidal, or rarely loculicidal dehiscence. Seeds 00, small; 

 embryo straight, minute, in the axis of soft fleshy albumen ; radicle 

 next the hilum. Herbs, seldom shrubs, with opposite (fig. 248), rarely 

 alternate, entire or divided, exstipulate leaves, which are often 3-5- 

 ribbed. The plants of the order are distributed generally over the 

 globe, inhabiting both cold and warm regions. They are rare in the 

 arctic and antarctic islands. They exhibit great varieties of colours, 

 and many are prized for their beauty. There are two suborders : 

 1. Gentianeas, aestivation of corolla imbricate-twisted, leaves opposite, 



