BiGNONIALES.] 



GESNERACEiE. 



671 



Fig. CCCCXLIX. 



Order CCLX. GESNERACE^.— Gesnerworts. 



Gesnerieae, Rich, et Juss. Ann. Miis. 5, 428. (1804) ; Kunth in Humb. N. G. et Sp. 2. 392 • Lindlfv in 

 Bot. Reg. 1110.— Gesneriace.-e, lAnk Hanb. 1.504. (1829); DC. i'rodr. 7. 523.— Ges'nerea> Von 

 Martins Nov. Gen. Bras. 3. 68. (1829) ; Barfl. Orel. Nat. 174.— Gesneraceac, Ed. pr. ccxv (183()> • 

 Endl. Gen. clii.— Cyrtandracea?, Jack in Linn. Trans. 14. 23. {n-ad 1822, in May) ; Alph. DC. 

 Prodr. 9. 258 ; Ed. pr. ccxii.— Didymocarpeae, Don in Edin. Phil. Trans. 7. 82. (1822, July). 



Diagnosis. — Bignmial Exogens, with parietcd placentce, capsular or baccate fruit, an em- 

 bryo vnth minute cotyledons, and a long radicle. 



Soft- wooded, somewhat fleshy, herbs or slunibs, occasionally ha\'ing a climbing or 

 creeping nmnner of gi-owth, and frequently springing from scaly tubers. Leaves 

 rugose, mthout stipules, generally oppo- 

 site or whorled. Flowers showy, in 

 racemes or panicles, rarely solitary, yel- 

 low, scarlet, violet, or white. Calyx half 

 adherent, 5-parted, with a valvate or open 

 sestivation. Corolla monopetalous, tubu- 

 lar, more or less irregular, 5-lobed, with 

 an imbricated sestivatiou. Stamens 2, or 

 4, didynamous ; anthers often cohering, 

 2-celled, innate, with a thick tumid con- 

 nective ; the rudiment of a fifth stamen 

 is present. Ovary half superior, 1-celled, 

 with 2 fleshy 2-lobed parietal polysper- 

 mous placentae, placed right and left of 

 the axis ; surroimded at its base by glands 

 or a fleshy rhig ; style continuous \rith 

 the ovary ; stigma capitate, concave ; 

 ovules 00, anatropal. Fniit capsular or 



succulent, superior, 1-celled, with 2 opposite lateral placentae, each consisting of 2 plates. 

 Seeds very munerous, minute ; embryo erect, in the axis of fleshy albumen, with the 

 cotyledons much shorter than the radicle ; testa thin, with very close fine oblique veins, 

 sometimes extended into long hairs, or even flattened into a Aving. 



These little plants (for they seldom rise above the statm'e of bushes, and are generally 

 mere herbs) have somewhat the appearance of Figworts, or of diminutive Bignouiads, 

 and have been even referred to those Orders. They, however, differ from all the present 

 AUiance in the very small size of their cotyledons as compared with their long radicle, 

 and their absolutely parietal placentation ; in addition to which they have a gi-eat ten- 

 dency to form an inferior ovary, and thus lead towards the Campanal Alliance m another 

 part of the series . To Eccremocarpus, a genus of Bignouiads, they appx'oach nearly, 

 as will be seen by refennng to p. 675; but in that plant the winged seeds and large 

 leafy cotyledons point too plainly to Bignouiads to be mistaken. Gesnerworts also 

 approach Broomrapes in their parietal placentation. 



The Suborder Cyrtandreae, usually regarded as a distinct group, has been removed 

 to Gesnerworts by Dr. Brown, and with justice, there being no sufficient distinction 

 between them. (See HorsfieWs Plantce Javanicce, p. 105). It is chiefly remark- 

 able for the long threads that teraiinate the seeds of certain genera, for their double 

 revolute placentae, and in some cases for their long, slender, sUiquose capsules. They 

 pass into Bignouiads through Incarvillea. 



The two Sub-orders have a very different geographical distribution. Gesnerese, which 

 are common in our gardens, are exclusively inhabitants of the tropical or warmer parts 

 of America. The Cyrtandrese, on the contrary, are spread over many parts of the world, 

 although chiefly confined to the eastern parts. Some occur in Europe, as Ramondia 

 and Haberlea ; others gi'ow in the cooler parts of Asia ; such are Baca and llehmannia. 

 Klugia is Mexican, Streptocarpus is from the Cape of Good Hope ; but it is in the 

 warm valleys of the Himalayas, and in the damp regions of the Indian Archipelago, 

 that they are most abundant, under the forms of Chirita, Calosacme, iEschynanths, and 

 Didymocarps. Fieldia is from New Holland, and several CjTtandras from the Sandwich 

 Islands. 



Fig. CCCCXLIX.— HypocjTta gracilis. 

 3. seed with its embryo exposed to view. 



-Martins. 1. section of a flower ; 2. cross section of a fruit 



