CORTUSALES. G37 



Alliance XLVII. CORTUSALES.— The Gortvsal Alliance. 



Diagnosis. — Pengynous Exogens,ivith monodicklaraydeoiisjlotcers, a free central placenta ^ 

 and an embryo lying among a large quantity of albumen. 



The Cortusal Alliance is distinctly limited among Perigynous Exogens by its free 

 central placenta, and an embryo lying in the inside of the albumen. By this last 

 circumstance it is separated from the Ficoidal Alliance, which has also a free central 

 placenta. There is this other essential difference, that the tendency of Ficoidals 

 is towards a polj'petalous or apetalous structure, while that of Cortiisals is towards a 

 monopetalous condition. In general, moreover, the albumen of the latter is extremely 

 abundant and hard ; but Leadworts have it insignificant in quantity, and mealy, in which 

 latter respect they correspond with Ficoidals. 



In a collateral way these plants may be brought in contact with Nightshades through 

 Frimworts, mth Sapotads and Ebenads through Ardisiads, and with Phloxworts 

 through Hydrophyls, which last offer the best transition to the Echial Alhance. 



In Ribworts the placentation is less ob\aously central than in the other Orders, but it 

 really is so, as is shown in speaking of those plants. In fact, the placenta of Hydrophyls 

 and Ribworts is of quite the same nature. 



|244. R^ 



Natural Orders of Cortusals. 

 Stamens altomate mth the petals. Styles 2. Inflorescence cir ..,.. nx.TM>r>T,tivTT »^i:-r 



cinate J 



Stamens opposite the petals. Fruit membranous, one-seed fd.\ c,,^ ■PrTT„,,.r.TXT.r>^^ 



Styles 5. Stem herbaceous J 



Stamens alternate with the petals. Style I. Inflorescence straight. 246. Plantaginace^. 

 Stamem opposite the petals. Fruit capsular, many-seeded. \2^^ PRiMULACEiE 



Style 1 . Stem herbaceous J ' 



Stamens opposite the petals. Fruit indehiscent, drupaceous. \(j,r. Mvwctvapf^? 



Style 1 . Stem woody J 



