BOTANY. 181 



fewer or more iiuraerous, inserted either on the disk or between the glands 

 and the ovary; filaments distinct or very slightly united at the base; 

 anthers introrse (the pistil of the staminate flowers either rudimentary or 

 entirely wanting). Ovary composed of three (rarely two to five) united 

 carpels ; styles partl}^ or completely united ; ovules solitar}' in each cell ; 

 erect or ascending ; sometimes two, the upper one ascending, the lower 

 suspended ; rarely three or more. Fruit two- to three-celled, capsular, 

 vesicular, or samaroid, or frequently fleshy and indehiscent. Seeds one to 

 three in each cell, usually arilled, without albumen. Embryo rarely straight ; 

 the cotyledons usually incumbent on the radicle, or spirally convolute, 

 sometimes combined into a thick mass. Trees or tendril-bearing shrubs or 

 herbs. Leaves alternate, usually compound and exstipulate, often marked 

 with pellucid lines or dots. Flowers small. Tribe 1. Sajnndeoe. Ovary 

 with one ovule in each cell. Embryo curved or rarely straight. Examples : 

 '" Cardiospermum, *Sapindus, Paullinia. Tr'ihe 2. Dodonceaceoi. Ovary with 

 two to three (rarely more) ovules in each cell. Embryo spirally convolute. 

 Example : *Dodün8ea. 



The entire order embraces nearly sixty genera; of which three, with as 

 many species, are North American. The fruit of Sapindus saponaria, 

 known in theAVest Indies as Soap berries, supplies a substitute for soap. 



Paullinia pinnata (South America) {pi. Q'd., fig. 14) ; a-d. 



Order 180. Hippocastaneace^, the Horse-Chestnut Family. Sepals 

 five, usually united into a campanulate or tubular five-toothed calyx ; 

 aestivation imbricated. Petals five, or four by the suppression of the 

 inferior one, commonly unequal and irregular, unguiculate, hypogynous. 

 Stamens six to eight, commonly seven, distinct, unequal, inserted upon the 

 hypogynous disk ; anthers oval, versatile. Ovary roundish, composed of 

 three united carpels, three-celled, with two collateral ovules in each cell ; 

 style filiform, acute. Fruit subglobose, coriaceous, three- (or frequentl}^ by 

 suppression one- to two-) celled, two- to three-valved, with loculicidal 

 dehiscence. Seeds solitary or very few, large, with a smooth or shining 

 testa, and a broad pale hilum, somewhat campylotropous, with no albumen. 

 Cotyledons very thick and fleshy, gibbous, cohering, remaining under ground 

 in germination ; radicle conical, curved ; ])lumale large, two-leaved. Trees 

 or shrubs. Leaves opposite (in Ungnodia alternate), exstipulate, compound ; 

 leaflets serrate. Flowers showy ; pedicels articulated. This order, composed 

 of the three genera Aesculus, Pavia, and Ungnodia, is North American, 

 excepting a single species, Aesculus hippocastaneum, from Thibet. Native 

 species of Aesculus are known in the United States as Buckeyes. The 

 powdered seeds of A. pavia may be used like Cocculus Indiens, to stupefy 

 fish. The root also may be used as a substitute for soap in washing woollen 

 cloths. 



Aesculus pavia, Small Buckeye (United States) {pl.QQ^ fig. 15); «, a 

 flowering branch ; J, upper and lower petals ; c, vertical section of ovary ; 

 ^7, fruit. 



Order 181. Aceracejs, the Maple Family. Calyx divided into five, 

 rarely into four or nine parts, with an imbricated aestivation. Petals equal 



181 



