113 



an imbricated calyx, unsymmetrical flowers, definite erect ovules, undivided 

 petals without appendages, dehiscent fruit, and compound palmate leaves. 

 Anomalies. 



Essential Character. — Calyx campanulate, 5-lobcd. Petals 5, or 4 by the abortion of 

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

 nous 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 a broad pale 

 hilum ; albumen none ; embryo curved, inverted, with fleshy, very thick, gibbous, cohering 

 cotyledons, germinating under ground; plumnla unusually large, 2-lcavecf; radicle conical, 

 curved, turned towards the hilum. — 'Trees or shrubs. Learn opposite, without stipidce, 

 compound, quinate or septenatc. 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 Hippocastanere to Sapindaceas ; the same 

 character brings them near Acerineee, 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 employed as a 

 sternutatory. The bark of the common Horse Chestnut is bitter, astringent, 

 and febrifugal. 



Examples. yEsculus, Pavia. 



XCIX. RHIZOBOLESE. 



RhizobolejE, Dec. Prodr. 1. 599. (1824) ; Cambessedes in Aug. St. Hil. Fl. Bras. Merid. 



1. 322. (1827.) 



Diagnosis. Polypetalous dicotyledons, with hypogynous indefinite sta- 

 mens, 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. Sta- 

 mens 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 combined nuts, 

 part of which are sometimes abortive; each nut indehiscent, 1-seeded, 1-celled, with a thick 

 double putamen. Seed reniform, without albumen, with a funiculus which is dilated into a 

 spongy excrescence ; embryo very large, constituting nearly the whole of the almond-like 

 substance of the nut, with a long 2-edged cauliculus, having two small cotyledons at the top, 

 and lying in a furrow of the radicle. — Trees. Leaves opposite, stalked, compound, without 

 stipule. Flowers racemose. 



Affinities. A very distinct order, related on the one hand to Anacardi- 

 aceae, and particularly to Mangifera, but perhaps rather to be associated with 

 Sapindaceae, in consideration of its hypogynous flowers and its fruit ; in some 



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