612 



GENTIANACE^. 



[Perigynous Exogens. 



Order CCXXXVI. GENTIANACEiE — Genttanworts. 



Gentianese, Juss. Gen. 141. (1789) ; R. Brown Prodr. 449 ; Von Martins Nov. Gm. ^c. 2. 132 ; Sarfl. 

 Ord. Nat. 199 ; Royle's Illustrations, 27() ; Endl. Gen. cxxxiv. ; Grisebach Monogr. (1836) ; Id. in 

 Atph. DC. Prodr. 9. 38.— Desfontaineae, Endl. Gen. p. 669. 



Diagnosis. — Gentianal Exogens, ivith no stipules, simple stigmas at the end of a manifest 

 style, parietal placenteB, and regular floioers. 



Herbaceous plants, seldom shinibs, generally smooth, sometimes twining. Leaves 

 opposite, entire, without stipules, sessile, or having their petioles confluent in a little 



Fig. CCCCXIV 



sheath, in most cases 3- 5-ribbed ; very rarely brown and scale-Hke ; sometimes alter- 

 nate. Flowers terminal or axillary, regular, or very seldom irregular. Calyx divided, 

 inferior, persistent. Corolla monopetalous, hypogynous, usually regular, and persistent ; 

 the limb regular, sometimes furnished with delicate fringes, its lobes of the same number 

 as those of the calyx, generally 5, sometimes 4, 6, 8, or 10, occasionally extended at the 

 base mto a bag or spur, with a plaited, or folded, or imbricated twisted aestivation. 

 Stamens inserted upon the corolla, all in the same line, equal in number to the segments, 

 and alternate with them ; some of them occasionally abortive. Ovary composed of 

 2 carpels, 1- or partly 2-celled, many-seeded. Style 1, continuous with the ovary ; stig- 

 mas 2, right and left of the axis ; ovules 00, anatropal, parietal. Capsule or beny 

 many-seeded ; when 2-valved, the margins of the valves turned inwards, and bearing the 

 seeds. Seeds small ; testa single ; embryo minute in the axis of soft fleshy albumen ; 

 radicle next the hilum. 



This Order is very near that of Dogbanes, from which it differs in the herbaceous 

 habit, permanent corolla, entire ovary, parietal placentation, imbricated, not contorted 

 aestivation, want of milk, and usually capsular fruit. The ribbed leaves too afford, in 

 the majority of cases, a certain mark of distinction ; to this may be added bitterness. 

 Wherever the parietal placentae can be found, and this is usually the case, the recogni- 

 tion of the Order is very easy ; and in the anomalous genera, like Sebaea, in which a 

 partially 2-celled ovary exists, a little examination shows that in reality the placentae 

 merely meet at the base. From Figworts, in particular, this circumstance distinctly cuts 

 Gentians off", independently of their minute embryo and symmetrical flowers. Von Mar- 

 tins remarks that no Gentianworts except Tachia have a hypogynous disk ; and the two 

 carpellary leaves of which the fruit is formed are lateral, or right and left with respect 

 to the common axis of the mflorescence, theu' placentae bemg consequently anterior aiad 



Fig CCCCXIV. — Gentiana amarella. 1. section of the ovary of Chironia baccifera ; 2. section of the 

 ripe fruit ; 3. a seed ; 4. a vertical section of it. 



