COEOLLIFLOB^;. 307 



the regular corolla, the agreement of the number of stamens and lobes of 

 the corolla, and quincuncial aestivation divide Loganiaceae in most cases ; 

 and although the aestivation and the regular corolla occur sometimes in 

 the former Order, there are then usually alternate leaves and no stipules. 

 As observed by Bentham, this is hardly so much a Natural Order as a 

 receptacle for anomalous forms of several really natural groups, Rubiaceae, 

 Apocynaceae, Gentianaceae, &c. 



Distribution. A rather large group, the species of which are chiefly 

 tropical, but some are found in North America and Australia. 



Qualities and Uses. The plants belonging to this Order have mostly 

 powerful poisonous properties, in particular the genus Strychnos. S. 

 Nux-vomica bears the seeds known by its name, so noted for the presence 

 of Strychnia. S. toxifera is said to furnish the active ingredient of the 

 celebrated Woorali poison of Guiana. S. cogens is likewise used to poison 

 arrows in Central America. S. Tieute (the bark of the root) yields the 

 Java poison called Upas Tieute. Many seem to be free from strychnia as 

 regards the bark ; for that of S. Pseudoquina is used as a substitute for 

 Cinchona in Brazil, that of 8. Nux-vomica also,and the wood of S. ligustrina, 

 called Lignum colubrinum. S. potatorum, an East-Indian species, is called 

 the Clearing-nut ; and it is said that, when its seeds are rubbed round in a 

 vessel containing muddy water, it causes the impurities to settle. The 

 seeds from the Philippines, known as St. Ignatius's Beans, have been 

 described as the seeds of a plant called Ignatia amara ; but are probably 

 those of an unknown Strychnos, perhaps multiflora, which grows on those 

 islands. The species of Spigelia are aero-narcotic ; S. marilandica, the 

 Carolina Pink-root, and 8. Anthelmia are used as vermifuges, but are 

 somewhat dangerous, sometimes producing spasms and even convulsions. 

 Potalia amara is bitter, acrid, and emetic. 



GENTIAN ACE^E. THE GENTIAN OBDEB. 



Coh. Gentianales, Senth. et Hook. 



Diagnosis. Smooth herbs, with a bitter juice, opposite and 

 sessile, mostly simple, entire, and strongly ribbed leaves, without 

 stipules ; flowers regular, with a persistent calyx, with stamens as 

 many as the lobes of the usually withering-persistent corolla, and 

 which are convolute (rarely imbricated, and sometimes valvate) in 

 the bud ; ovary 1-celled, with two parietal placentas, projecting 

 more or less toward the centre ; the fruit mostly a 2-valved, septi- 

 cidal, many-seeded capsule, sometimes with a fleshy pericarp; 

 seeds small ; embryo minute in the axis of fleshy perisperm. 



ILLUSTRATIVE GENERA. 



Tribe 1. EXACEJE. Corolla-lobes contorted dextrorse; ovary ^-celled. 



Exacum, L. 



Tribe 2. CHIRONIEJS. Corolla-lobes dextrorse ; ovary 1-celled. Chironia, L. 

 Tribe 3. SWERTIEJE. Corolla-lobes auntorted or imbricate; ovary 1-celled; 



style short. Gentiana, L. 



