128 HIPPOCASTANACEAE 



1. S. trifolia L. Bladdeenut. 4°-12° high: leaflets ovate, acumi- 

 nate, pointed, finely serrate. — Common along moist rocky bluffs, espe- 

 cially in the northern part. May. 



Family 76. ACERACEAE St. Hil. 

 Trees with opposite leaves and regular polygamous or dioecious flowers. 

 Sepals five. Petals five (or absent), inserted on the margin of the disk. 

 Stamens 3-12. Ovary 2-lobed, 2-celled, 4-ovuled. Fruit of two, winged, 

 1-seeded samaras. 



1. ACER L. 

 With characters of the family. 



Leaves simple. 



Leaves silvery white beneath. 1. A. saccharinum. 

 Leaves not silvery white beneath. 



Leaves smooth beneath. 2. A. Saccharum. 



Leaves minutely downy beneath, 3. A. nigrum. 



Leaves 3-7-foliolate. 4. A . Negundo. 



1. A. saccharinum L. White Maple. 50°-125° high : flowers ap- 

 pearing before the leaves, in sessile lateral clusters: petals none: ovary 

 tomentose: leaves deeply 5-lobed, the lobes irregularly dentate. — Com- 

 mon along streams. March-April. 



2. A. Saccharum Marsh. Sugar Maple. 30°-100° high: flowers 

 appearing with the leaves, drooping on long capillary hairy pedicels : 

 petals none : lea,ves 3-5-lobed, the sinuses rounded and the lobes irregu- 

 larly sinuate. — Bluffs from Courtney to Levasy, but uncommon. April- 

 May. Our form is var. harhatum ( Michx. ) Trelease. 



3. A. nigrum Michx. Black Sugae Maple. Differs from the last 

 in the leaf-lobes being broader and more entire, and in the leaves being 

 downy beneath. — Abundant in the northeastern part. April-May. 



4. A. Negundo L. Box Elder. 30°-60° high: flowers dioecious, 

 appearing before the leaves, the fertile racemose : leaves 3-7-foliolate, 

 the ovate leaflets irregularly dentate. — Common throughout, especially 

 along bluffs. April-May. 



Family 77. HIPPOCASTANACEAE T. & G. 



Woody plants with opposite palmatel^' several-foliolate leaves, and 

 polygamous flowers in terminal panicles. Calyx 5-lobed. Petals 4-5, 

 unefiual, clawed. Stamens about 7. Ovary 3celled, 8-ovuled. Capsule 

 hard and leathery. 



1. AESCULUS L. 



Characters of the family. 



1. A. glabra arguta (Buckley) Robinson. Buckeye. Horse Chest- 

 nut. 3°-30° high : leaflets 5-9, ovate-lanceolate, serrate, pubescent or 

 becoming glabrate : flowers yellow : stamens exserted : fruit at maturity 

 nearly smooth. — Abundant along streams. April-May. 



