115 



XCVIIl, HIPPOCASTANEtE. The Horse-Chestntjt Tribe, 



HippocASTANE^E, Dec. TMorie, ed. 2. 244.(1819); Prodr. 1. 597. (1824).— 

 Castaneace^e, Link Enum. 1. 354. (1821.) 



Diagnosis. Polypetalous dicotyledons, with hypogynous definite sta- 

 mens, concrete carpella, an ovarium of several cells with the placentae in the 

 axis, an imbricated calyx, unsymmetrical flowers, definite erect ovules, un- 

 divided petals without appendages, dehiscent fruit, and compound palmate 

 leaves. 



Anomalies. 



Essential Character — Calyx campauulate, 5-lobed. Petals 6, or 4 by the abor- 

 tion of one of them, unequal, hypogynous. Stamens 7-8, distinct, unequal, inserted upon 

 a hypogynous disk ; anthers somewhat incumbent. Ovarium roundish, 3-cornered, 

 3-celled; style 1, filiform, conical, acute; ovula 2 in each cell. Fruit coriaceous, 1- 2- or 

 3-valved, 1- 2- or 3-celled, 1- 2- or 3-seeded. Seeds large, roundish, with a smooth shining 

 coat, and abroad pale hilum; albumen none ; embryo curved, inverted, with fleshy, very 

 thick, gibbous, cohering cotyledons, germinating under ground ; plumula unusually large, 



2-leaved ; radicle conical, curved, turned towards the hilum Trees or shrubs. Leaves 



opposite, without stipulw, compound, quinate or septenate. Racemes terminal, somewhat 

 panicled ; the pedicels with an articulation. 



Affinities. The want of symmetry in the parts of the flower, and their 

 compound leaves, approximate Hippocastanese to Sapindacege ; the same 

 character brings them near Acerinese, from both which they are distinguished 

 by the structure of their fruit and seeds. They also approach Rhizobolese, 

 as is stated in speaking; of that order. 



Geography. The north of India and North America contain the few 

 species that belong to this order. 



Properties. Handsome trees or small bushes, chiefly remarkable for 

 their large seeds, with an extensive hilum. These seeds contain a great 

 quantity of starch, which renders them nutritive for man and many other 

 animals. They also contain a sufficient proportion of potash to be useful 

 as cosmetics, or as a substitute for soap ; they are bitter, and have been em- 

 ployed as a sternutatory. The bark of the common Horse Chestnut is bitter, 

 astringent, and febrifugal. 



Examples, ^sculus, Pavia. 



XCIX. RHIZOBOLE^. 



JtHizoBOLEii;, Dec. Prodr. 1. 599. (1824) ; Camhesstdes in Aug. St. Hit. Fl. Bras. Merid. 



1. 322. (1827.) 



Diagnosis. Polypetalous dicotyledons, with hypogynous indefinite 

 stamens, concrete carpella, an ovarium of several cells : with solitary peltate 

 ovules, an imbricated calyx, exstipulate compound leaves, and round anthers 

 bursting longitudinally. 



Anomalies. 



Essential Character. — Sepals 5, more or less combined, imbricated in aestivation. 

 Petals 5, thickish, unequal, arising along with the stamens from a hypogynous disk. 

 Stamens extremely numerous, slightly monadelphous, arising in a double row from a disk, 

 the innermost being shorter and often abortive ; anthers roundish. Ovarium superior, 

 4-celled, 4-seeded ; styles 4 ; stigmas simple ; ovula peritropal. Fruit formed of 4 com- 

 bined nuts, part of which are sometimes abortive ; each nut indehiscent, 1-seeded, l-celled, 

 with a thick double putamen. Seed reniform, without albumen, with a ftmiculus which 



