Trees of New York State 379 



SOAPBERRY FAMILY. SAPINDACEAE 



Trees, shrubs, lianas, or herbaceous vines with watery juice, 

 chiefly alternate componnd estipulate leaves, and mainly polyga- 

 mous unsymmetrical flowers. A large family comprising more 

 than one hundred genera and one thousand species widely dis- 

 tributed in the tropical and warm temperate regions of the world. 

 But one genus, Ae^culus, is represented by a naturalized arbores- 

 cent form in New Yoi-k State. 



Leaves alternate (opposite in one genus), pinnate or palmate, persistent or 

 deciduous, estipulate. Flowers regular or irregular, polygamous; sepals or 

 ealyx-lobes 4—5, imbricated in the bud; petals 3-5, imbricated in tlie bud; disk 

 annular, fleshy; stamens generally 7-10, inserted on the disk, with free fila- 

 ments and introrse 2-celled anthers; pistil consisting of a 2-4-celled ovary sur- 

 mounted by a terminal style and capitate or lobed stigma; ovules solitary or 

 2 in a cell. Fruit a drupe or capsule; seed usually solitary by abortion, exal- 

 buminous. 



THE HORSE-CHESTNUT AND BUCKEYES. 



Genus AESCULUS L. 

 Trees and shrubs with stout branchlets, large buds, ill-scented 

 bark, and showy paniculate flowers. Aesctdus includes ten or 

 twelve species which are found in North America and Eurasia. 



Leaves ojiposite, deciduous, digdtately compound, petiolate, estipulate; leaf- 

 lets 3-9, seiTate. Flotvers polygamous, showy, borne in large termintil panicles, 

 generally only the lower flowers fertile; pedicel jointed; calj^ campanulate, 

 5-lobed, the lobes unecpuil and imbricated in the bud; jjetals 4:-5, unequal, 

 clawed; disk hypogynous, aimular; stamens chiefly 7, with elongated filiform 

 unequal filaments and introrse, longitudinally dehiscent anthers; pistil con- 

 sisting of a 3-celled sessile ovary surmounted by a slender, elongated curved 

 style and capitate stigma ; ovules 2 in each cell. Fruit a coriaceous, 3-valved, 

 1-2 seeded capsule, loculicidally dehiscent; seeds large, globose or hemispher- 

 ical, smooth, lustrous, browii, with large pale hilum, exalbuminous ; cotyledons 

 thick fleshy, hypogean. 



Aesculus is represented in New York State by but the one 

 naturalized species A Hipjjocasfanuni L.. a native of the Orient. 



BUCKTHORN FAMILY. RHAMNACEAE 



Small trees and erect or climbing shrubs with bitter bark, simple 

 and mainly alternate leaves, and perfect, polygamous, or dioecious 

 inconspicuous flowers. The Rhamnaceae include about forty-five 

 genera and some six hundred species, chiefly natives of the tropical 

 and warmer parts of the temperate regions. But one genus, 

 Rhamnus, is represented by an arborescent species in New York 

 State. 



