594 GENTIANALES. [Pkkigynous Exogens. 



Alliance XLV. GENTIANALES.— The Gentianal Alliance. 



Diagnosis.— Perigynous Exogens, with dichlamydeous monopetalous floivers, axile or 

 parietal placenta, and a minute embryo, or with the cotyledons much smaller than the 

 radicle, lying in a large quantity of albumen. 



Here we find ourselves among the truly monopetalous Orders of the French school. 

 Previously a monopetalous structure was an exception rather than a rule ; but now a 

 separation of petals forms the exception. Tendencies have assumed a new du-ection. 

 • The Alliance differs from that of Solanals in having a minute embryo and much albu- 

 men, and from Cortusals in the placenta never being free and central. It touches bo- 

 lanals at Nightshades themselves, which, if they had parietal placentae might often be 

 mistaken for Gentianworts ; and at Dogbanes, whose minute embryo offers one ot the 

 principal reasons for not associating them in the same Alliance as Asc epiads. \\ ith 

 Cortusals Gentianals come in contact through Ebenads, which are very like Ardisiaus, 

 and Diapensiads, which may be compared to Primworts. To Bignomals they are very 

 closely allied through Broomrapes and Stilbids, which put on the peculiar aspect of that 

 Alliance. 



N.vtiral Orders of Gentianals. 



Stipides 0. Stigmas simple, sessile, radiating 229. Ebenace.e. 



Stipules 0. Stigmas simple, at the end of a manifest style. Pla- "1 230> Aquifoliace.e. 



rentes axile. Seeds definite, pendulous. Corolla imbricated .} 

 Stipules 0. Stigmas collected into a massive head, expanded of) 



the base in the form of a ring or membrane, and contracted in J> 231. Apocy.nace f.. 



the middle. (Albumen sometimes 0) J 



Leaves opposite, with intervening stipules ........ 232. Loganiace.e. 



Stipules 0. Stigmas simple, at the end of a manifest style. Pla- \ 233 Di apensiace.k. 



centee axile. Seeds indefinite, peltate. Stamens inter petalous . J 

 Stipides 0. Stigmas simple, at the end of a manifest style. Pla- "I 



centee axile. Seeds definite, erect. Corolla valrate. Flowers p34. Stilbace.e. 



unsymmetrical J 



Stipules 0. Stigmas simple, at the end of a manifest style. Pla- 1 235 Orobanchace.e. 



centee parietal. Flowers didynamous J 



Stipules 0. Stigmas simple, at the end of a manifest style. Pla- 1 236 Gentianace.e. 



centm parietal. Flowers regular J 



