644 TREES OF NORTH AMERICA 



below the middle, introrse, 2-celled, the contiguous cells opening longitudi- 

 nally ; ovary sessile, oblong or lanceolate, 3-celled, echinate or glabrous, rudi- 

 mentary in the staminate flower ; style slender, elongated, generally more or 

 less curved ; stigma terminal, entire, mostly acute ; ovules 2 in each cell, borne 

 on the middle of its inner angle, amphitropous, the upper ascending, the micro- 

 pyle inferior, the lower pendulous, the micropyle superior. Fruit an echinate 

 roughened or smooth coriaceous capsule, 3-celled and loculicidally 3-valved, 

 the cells 1-seeded by abortion, often by suppression 1 or 2-celled, and then 

 1 or 2-seeded, the remnants of the abortive cells and seeds commonly visible 

 at its maturity. Seeds without albumen, round when one is developed, or, 

 when more than one, flattened by mutual pressure ; seed-coat coriaceous, chest- 

 nut-brown, smooth and shiny, with a broad opaque light-colored hilum ; em- 

 bryo filling the cavity of the seed ; cotyledons very thick and fleshy, often 

 conferruminate, unequal, incurved on the short conical radicle, remaining under 

 ground in germination ; plumule conspicuously 2-leaved. 



The Horsechestnut family is composed of the widely distributed genus JEs- 

 culus and of Billia, Peyr., a genus of two species of Mexican and Central 

 American trees, differing from ^Esculus in its 3-foliolate leaves. 



1. -SJSCULUS, L. 



Characters of the family. 



JEsculus with ten or eleven species is represented in the floras of the three conti- 

 nents of the northern hemisphere. Jt produces soft straight-grained light-colored 

 wood and bitter and astringent bark. The seeds contain a bitter principle, sesculin. 

 jEsculus Hippocastanum, L., of the mountains of Greece, the common Horsechestnut 

 of gardens, is largely planted as an ornamental tree in all countries with temperate 

 climates, and now occasionally grows spontaneously in the eastern states. 



The generic name is the classical name of an Oak-tree. 



CONSPECTUS OF THE AKBORESCENT SPECIES OF NORTH AMERICA. 



Winter-buds without resinous coating. 



Calyx campanulate ; leaflets mostly glabrous below. 



Petals nearly equal, shorter than the stamens ; fruit tuberculate. 



1. JE. glabra (A, C). 



Petals unequal, longer than the stamens ; fruit smooth. 2. JE3. octandra (A, C). 

 Calyx tubular ; leaflets tomentulose below ; petals unequal, shorter than the stamens ; 

 fruit smooth. 3. JB. austrina (C). 



Winter-buds resinous. 



Calyx 2-lobed; petals nearly equal, much shorter than the stamens ; fruit smooth. 



4. 2E. Californica (G). 



1. .ffisculus glabra, Willd. Ohio Buckeye. Fetid Buckeye. 



Leaves with slender petioles 4'-6' long, enlarged at the ends and often furnished 

 on the upper side with clusters of dark brown chaff-like scales surrounding the base 

 of the petiolules, and 5-7, usually 5, oval oblong or obovate acuminate leaflets grad- 

 ually narrowed to the elongated entire base, finely and unequally serrate above, at 

 first sessile, becoming slightly petiolulate at maturity, covered on the lower surface 

 like the petioles when they first appear with short soft deciduous pubescence, and at 

 maturity glabrous with the exception of a few hairs along the under side of the con- 

 spicuous yellow midribs and in the axils of the principal veins, yellow-green, paler 



