681 



EXOGENS. 



EXOGENS, 



eel 



XXXIII. CAMPANALES. Flowers dichlamydeous, monopetolous. 

 Embryo with little or no albumen. 



Campanulacea;. Ovary 2 or more celled. Anthers free, or half 

 united. Stigma naked. Corolla valvate, regular. 



Jjobeliacece. Ovary 2 or more celled. Anthers syngenesious. 

 Stigma surrounded by hairs. Corolla valvate, irregular. 



Goodeniacea. Ovary 2 or more celled. Anthers syngenesious or 

 free. Stigma indusiate. Corolla induplieate. 



Stylidiacece. Ovary 2 or more celled. Stamens and styles united 

 into a column. Corolla imbricated. 



Valerianaceff. Ovary 1-celled. Corolla imbricated. Anthers free. 

 Ovule pendulous. Albumen none. 



Dipsacace(e. Ovary 1-celled. Corolla imbricated. Anthers free. 

 Ovule pendulous. Seeds albuminous. 



Calyceracer?. Ovary 1-celled. Corolla valvate. Anthers synge- 

 nesious. Ovule pendulous. Seeds' albuminous. 



Asteracece. Ovary 1-celled. Corolla valvate. Authors syngenesious. 

 Ovule erect. Albumen none. 



XXXIV. MYRTALKS. Flowers dichlamydeous, polypetalous. Pla- 

 centa; axile. Embryo with little or no albumen. (Occasionally 

 monochlamydeous.) 



Combretacea;. Ovary 1-celled. Ovules pendulous. Leaves dotless. 

 Seeds without albumen. Cotyledons convolute. 



Alangiacea. Ovary 1-celled. Ovules pendulous. Leaves dotless. 

 Seeds albuminous. Cotyledons flat. 



Chamalauciacere. Ovary 1-celled. Ovules ascending. Leaves 

 dotted. Embryo fused into a solid mass. 



Haloragacea. Ovary with more than 1 cell. Flowers polypetalous 

 or apetalous. Calyx open, minute. Stamens definite. Ovules pen- 

 dulous. Cotyledons minute. (Occasionally 1-celled.) 



Onagracae. Ovary with more than 1 cell. Flowers polypetalous 

 or apetalous. Calyz valvate. Stamens definite. Ovules horizontal 

 or ascending. Cotyledons flat, much larger than the radicle. 



Bhizophoracett. Ovary with more than 1 cell. Flowers polypeta- 

 loua. Calyx valvate. Stamens indefinite. Cotyledons flat, much 

 shorter than the radicle, which germinates before the fruit falls. 



Btlvitiacece. Ovary with more than one cell. Flowers mono- 

 petalous, coronated. Calyx valvate. Stamens indefinite, mon- 

 adelphous. Cotyledons amygdaloid. 



MeltutomacefF. Ovary with more than 1 cell. Flowers polypeta- 

 loua. Calyx imbricated. Stamens definite. Anthers rostrate. 

 Leaves usually dotless. 



Myrtacea. Ovary with more than 1 cell. Flowers polypetalous or 

 apetalous (or valvate). Calyx imbricated. Stamens 00. Anthers 

 oblong. Leaves usually dotted. 



Lesythidacem. Ovary with more than 1 cell. Flowers polypeta- 

 lous. Calyx valvate or imbricated. Stamens 00, in part collected 

 into a fleshy hood. Anthers oblong. Leaves dotless. 



XXXV. CACTAT.ES. Flowers dichlamydeous, polypetalous. Placenta; 



parietal. Embryo with little or no albumen. 



Ilomaliafea. Sepals and petals distinct. Stamens opposite the 

 petals. Styles separate. Ovules pendulous. 



Loatamr. Sepals and petals distinct. Stamens scattered. Styles 

 confluent. Ovules pendulous. Seeds albuminous. 



Cactacea. Sepals and petals numerous, indistinguishable. Stamens 

 scattered. Styles confluent. Ovules horizontal. Seeds without 

 albumen. 



XXXVI. GROSSALES. Flowers dichlamydeous, polypetalous. Seeds 

 numerous, minute. Embryo small, lying in a large quantity of 

 albumen. 



Groaulariacea. Fruit pulpy. Placenta) parietal. 



Ecalltmiacece. Fruit capsular. Pacentso axile. Style and stamens 

 definite. Calyx imbricated. 



Philadclphacerf. Fruit capsular. Placenta; axile. Styles disunited. 

 Stamens 00. Calyx valvate. 



Barrinytoniaceee. Fruit pulpy or fibrous. Placenta; axile. Style 1. 

 Stamens 00. Calyx imbricated. 



XXXVII. CiNCHONALES. Flowers dichlamydeous, monopetalous. 

 Embryo minute, lying in a large quantity of albumen. 



, Vacciniacea;. Stamens epigynous. Anthers opening by pores. 



Colivmelliacere. Stamens epipetalous, bursting longitudinally. 

 Anthers sinuous. Flowers unsymmetrical. 



C'inchonacea. Stamens epipetalous, bursting longitudinally. 

 Anthers straight. Leares with interpetiolar stipules. 



Caprifoliacere. Stamens epipetalous, bursting longitudinally. 

 Anthers straight. Fruit consolidated. Leaves without stipules. 



Oaliacece. Stamens epipetalous, bursting longitudinally. Anthers 

 straight. Fruit didymous. Leaves verticillate, without stipules. 



XXXVIII. UMBELLALES. Flowers dichlamydeous, polypetalous. 

 Seeds solitary, large. Embryo small, lying in a large quantity 

 of albumen. 



Afiacea. Fruit didymous, with a double epigynous disc. 

 Araliacece. Fruit not didymous, without a double epigynous disc, 

 3 or more celled. Peutamerous flowers. Corolla valvate. Leaves 



alternate, without stipules. Anthers turned inwards, opening 

 lengthwise. 



Cornacece. Fruit not didymous, without a double epigynous disc, 

 2 or more celled. Tetramerous flowers. Corolla valvate. Leaves 

 opposite, without stipules. 



Hamamelidaceie. Fruit not didymous, without a double epigy- 

 nous disc, 2-celled. Corolla imbricated. Leaves alternate, with 

 stipules. Anthers with deciduous valves. 



Bruniaceas. Fruit not didymous, without a double epigynous disc, 

 3- (or 1-) celled. Corolla imbricated. Leaves alternate, without 

 stipules. Anthers turned outwards, opening lengthwise. 



XXXIX. ASARALES. Flowers monochlamydeous. Embryo small, 

 lying in a large quantity of albumen. 



Santalacece. Ovary 1-celled. Ovulea definite, with a coated 

 nucleus. 



Loranthacece. Ovary 1-celled. Ovulea definite, with a naked 

 nucleus. 



Aristolochiacece. Ovary S-6-celled. Ovules 00. 



On this arrangement Dr. Lindley makes the following general 

 remarks : 



" The office of reproduction is, after that of sustaining life, the most 

 essential in the economy of plants and animals, and therefore the 

 modifications which are found in the organs of reproduction may be 

 expected to furnish the best characters for classification, after those of 

 nutrition. The latter have been already employed as the foundations 

 of the classes, as far as they appear susceptible of being so applied ; 

 the former, consisting of the stamens and pistil, have been little used 

 for the classes, and appear to present as many modifications as are 

 required for secondary divisions. That was the opinion of Linnams, 

 who adopted them in the construction of the classes and orders of 

 his sexual system ; but he mainly relied upon their number, which is 

 a circumstance of little or no importance, and where that was done 

 his classification proved useless ; but in those parts of the system in 

 which he made use of other circumstances, as in his Monadelphia, 

 Diaddphia, Tetradynamia, Didynamia, Synyenesia, &c., his divisions 

 ceased wholly or in part to be artificial, and although in soino 

 instances modified, still correspond essentially with the natural 

 orders of modern botanists. Nor did the importance of the stamens 

 and pistil escape the keen eye of Jussie'u, who relied upon them very 

 much in the construction of his ingenious system. In the first place 

 he separated from all other Exogens those which have the stamens 

 in one flower and the pistil in another, and he called them Diclinous, 

 and by this process he brought together a collection of natural orders 

 corresponding with the Monoecious and Dioecious plants of Linnaeus. 

 No one can doubt that this was a judicious step, and upon the whole 

 the plants collected in the Diclinous division resemble each other 

 more than they resemble anything else ; but he excluded a large 

 number of truly Diclinous plants, which are scattered over other parts 

 of his classification, and this has led to the idea that the distinction 

 itself was a bad one, an opinion in which I formerly concurred ; but 

 a more careful examination of it since, and an extensive acquaintance 

 with the vegetable kingdom, has entirely convinced me that we have 

 no available characters for breaking up Exogens into primary groups, 

 or sub-classes, superior to those of separated and united sexes, that 

 is to diclinism and hermaphroditism. Not that they are without 

 exceptions; to employ the forcible language of Jussieu himself: ' Ut 

 in prcecedente serie nonnullas diclinis hermaphroditis conmixtas 

 plantis admittit excepta;, sic in diclinum ordines quaedam irrepunt 

 hermuphrodita: ; cousentiente aut jubente natura, qufe stabiliores 

 interdum eludit regulas, noununquam instabilis ipsa aut abstrusis 

 legibus obtemperans.' (' Gen. PI." 384.) But if what are called poly- 

 gamous plants, that is to say, such as have a rudimentary pistil in 

 the male flowers, and rudimentary stamens in the female flowers, are 

 regarded as being hermaphrodite, as they surely are, and the idea of 

 a diclinous structure is limited to cases of a total separation of the 

 stamens and the pistil, these exceptions are reduced to a small and 

 unimportant number of no moment in a classification. For this 

 reason then the Diclinous sub-class of Jussieu is still preserved and 

 increased by modern discoveries, and improved by the expulsion of 

 such plants as Piper, Gnetum, Ulmus, and others, which belong to 

 hermaphrodite orders, or have other affinities than those suggested 

 by Jussieu. . In this way Exogens are broken xip into two groups, the 

 one Diclinous and the other Hermaphrodite. The latter is divided 

 by almost everybody into Polypetalous, Monopetalous, and Apetalous 

 sub-classes, following the old systematists who knew of little beyond 

 external characters, and had small acquaintance with any plants 

 except those of Europe. But all experience shows, what reason 

 seems to indicate, that no great natural combinations can be effected 

 by such distinctions. Exceptions to the constancy of such characters 

 are endless ; there is probably not one polypetalous order that is not 

 also apetalous, and many of them are even monopetalous, of which 

 Kueworts, Houseleeks, Anonads, Leguminous plants, Milkworts, and 

 many more afford familiar examples. The apetalous orders are 

 occasionally polypetalous, as in many genera of Buck-Wheats and 

 Daphnad's. The monopetalous structure becomes polypetalous in 

 all but a very few cases, even indeed in such natural orders as the 

 Primworts; and it even disappears altogether, an in Oliveworts and 



