668 BIGNONIALES. [Perigynous Exogens. 



Alliance XLIX. BIGNONIALES.— Tre Bigxonial Alliance. 



Diagnosis. — Perigynous Exogens, with didilamydeous, monopetalous, unsymmetrical 

 flowers, capsular or berried fruit, having its carpels quite consolidated, parietal 

 free central or axile placentce, and an embryo with little or no albumen. 



With Bignonials the series of PerigjTious Alliances closes, Gesnerworts passing as 

 directly into Bellworts among Carapanals as Figworts also pass into the Nightshades 

 among Solanals. The two are parallel instances. Nevertheless, it does not seem 

 expedient to place Gesnerworts at the end of the Bignonial Alliance, because it is 

 impossible to separate them from Bignoniads and Cresceutiads, or from Pedaliads, whose 

 hard bony fruit presents the nearest approach m this AUiance to the nuts of Echials. 

 We must, therefore, regard the passage of Bignonials into Campanals as being altogether 

 from the side of the series and not from its extremity. Another lateral affinity presents 

 itself between Butterwoi'ts and Primworts, in the Cortusal AUiance. The following \\ill, 

 therefore, express the bearing of Bignonials and other Alliances, better than a lineal 

 position : — 



Pedaliaceae. 



Gesneraceae. 



Crescentiaceee. Campjanals. 



Gentianacew. Bignoniaceae. 



Acanthacese. 



Scrophulariacese. Solanales. 



Lentibulariaceae. Cortusales. 



The Bignonial Alliance may be regarded, then, as the centre of a particular portion 

 of Exogens, round which several others are stationed in nearly equal degrees of 

 contigiiity. 



Natural Orders of Bignonials. 



Placerdce parietal. Fruit bony or capsular. Embryo cimyg-\cytQ PEDALrACF^ 



daloid. Radicle short j ' 



Placentce parietal. Fruit capsular or baccate. Embryo with X.^orv GpsNFRArFyF 



minute cotyledons. Radicle long J 



Placentce parietal. Fruit succulent, hard-shelled. Embryo Xcc^y rnpcppNTiArp 



amygdaloid. Radicle short j ' 



Placentce axile. Seeds winged, sessile, without albumen. Coty-^^f^.-y BirNONiACF 



ledons large, leafy j ~" 



Placentce axile. Seeds windless, attached to hard placental X^r-o Ap.xxH 



processes, without albumen. Cotyledons large, fleshy . .J ' 

 Placentce axile. Seeds albwninous. Cotyledons scarcely lai'ger "1 f,^ . SrRn 



than, or not so large as, the radicle J "" * ^^' 



Placenta free, central. Seeds minute, vnthout albumen. Coty-\^^^ y 



ledons much smaller than the radicle | ^o^. 1.entibulariace^. 



